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ACKNOWLEDGEMENT(1)
CHAPTER 1-INTRODUCTORY NOTES.(3)
CHAPTER 2- MECHANICS&laquo;&laquo;&laquo;...(20)
CHAPTER 3- OPTICS&laquo;&laquo;&laquo;&laquo;&laquo;&laquo;(59)
CHAPTER 4- HEAT &laquo;&laquo;&laquo;&laquo;&laquo;&laquo;..(84)
CHAPTER 5- ELECTRICITY&laquo;&laquo;....(91)
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CHAPTER
ONE
INTRODUCTORY
NOTES
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1.0
INTRODUCTION
1.1 AIMS
The aims of a course in physics practical may be summarized as follows:(i)
(ii)
(iii)
To emphasize the understanding of fundamental principles and laws of physics.
To develop the mind of a learner to be inquisitive and curious of what is
happening through experimentation.
To enable students familiarize themselves with scientific methods which include
observation, measurement, and manipulation of apparatus and be able to draw up
conclusions.
1.2 How to prepare for a physics practical
The student should be familiar with taking and reading measured values, using the
common apparatus.
The common apparatus include:Vernier caliper, metre rule, micrometer screw gauge, protractor, ammeter, voltmeter,
thermometer, measuring cylinder, stop clock and stop watch.
1.3 Instruments for linear measurements
In taking linear measurements an instrument is chosen according to the size of the
object.
The apparatus used for taking linear measurement are: - metre rule, varnier
calliper and micrometer screw gauge.
(i)
Metre rule
The metre rule is the most commonly used instrument to measure length to an accuracy
of 1 mm its scale is in cm and mm.
In this instrument 10 small divisions are equal to 1cm .
Therefore 1 small division is equal to 1mm
(ii) Vernier Calliper
This instrument carries two scales and is used for measuring length between 1 cm and 9
cm inclusive.
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Diagram
The reading is taken from the two scales
a) Main scale
b) Vernier scale
The main scale is graduated in centimeters (cm) while the vernier scale is constructed by
dividing 9 mm into 10 equal divisions. So each division on a vernier is equal to 0.1mm.
How to use a vernier calliper
x Close the external jaws of the vernier and check if the zero's of the main scale and
vernier scale coincide.
x Open the jaws of the instrument, place the object between them and close the jaws
so that they press tightly against the object, lock the locking screw.
x Record the reading on the main scale before the zero mark on the vernier.
x By looking at the vernier scale locate the division which coincides with the main
scale division.
x
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Note
x The main scale reading is recorded in centimeters, and
x Each division on the vernier scale is equal to (1/100) cm or 0.01 cm
Illustration
Find the reading of the vernier caliper shown below.
From above
The main scale reading = 3.70 cm
Vernier scale reading = 7div x 0.01 cm
= 0.07cm
Actual reading ൌ (3.70 + 0.07) cm
ൌ ૜Ǥ ૠૠcm
The reading of a vernier calliper is 3.77 cm.
Therefore all vernier calliper readings are first recorded in cm to two decimal places
(iii) micrometer screw guage
The micrometer screw guage is used for measuring smaller length of atmost 1 cm and
0.01 mm such as diameter of wire, thickness of metre rule etc.
The micrometer screw guage has two scales
a) The main scale is graduated in millimeters(mm)
b) The vernier scale which has either 50 or 100 divisions each of 0.01 mm.
Therefore the reading of a micrometer screw guage is to an accuracy of two
decimal places in mm.
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Diagram
How to use a micrometer screw guage
x Close the jaws to accommodate the object by rotating the thimble and lastly the
ratchet.
x Take the readings of main scale first,followed by circular vernier scale.
x The division on the circular vernier scale which coincides with the main scale line
is taken.
Actual reading = main scale reading + (No. of division x 0.01 mm on the circular vernier
scale.)
Illustration
Find the reading of the micrometer screw guage that is shown below?
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Main scale reading = 8.00 mm
= (9 x 0.01 mm)
= 0.09mm
= (8.00 ൅ 0.09)mm
ൌ8.09mm
N.B
For values required to be measured once in a physics practical, we take three readings at
different points of the object and then find the mean.
e.g measure the diameter ݀ of the wire.
݀ͳ /mm
݀ ൌ
݀ʹ /mm
݀ ͳ ൅݀ ʹ ൅݀ ͵
͵
݀͵ /mm
mm
1.4 Electrical Instruments
Ammeters and voltmeters are the most common instruments used in the laboratory for
electricity experiments.
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Their readings can be taken to an accuracy of a half the smallest division
(1) Ammeter
Find the reading of the ammeter scale shown below.
We find the scale
15divisions
= 0.5 A
1 small division =
ͲǤͷ
ͳͷ
A
ൌ ͲǤͲ͵‫ܣ‬
Actual reading = 0.5 + (3 division x 0.03)
= (0.5 + 0.09)
= 0.59A
(Accuracy to a two decimal places)
NB: The same can be done for a voltmeter.
Exercise
Find the reading for each of the instruments as shown below.
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1.5 Heat instruments
In heat experiments the most common apparatus used are; thermometers, calorimeters,
measuring cans e.t.c . Some are shown below.
THERMOMETERS
MEASURING CAN
1.6 Time instruments
In measuring time most laboratories are equipped with stop clocks and stop watches.
The unit of measurement is seconds (s). The degree of accuracy of a stop watch is to two
decimal places while for a stop clock is to one decimal place
1.7
Inside the laboratory (Starting a physics practical Examination)
A physics practical exam UCE (P535/3) or (P535/4), consist of three question
A candidate is to attempt two questions in all .The time allowed is 2 hours 15 minutes. A
candidate is not allowed to start working with the apparatus for the first 15 minutes and
during this time a candidate is expected to be planning.
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Note
In some practical exam, some questions are compulsory. Candidates need to choose
from either questions provided.
(a) What is expected during the planning process:x The student should be reading the experimental procedures carefully and write the
title of the experiment in which he/she has the apparatus.
x Study the diagram which is a guide to the arrangement of apparatus.
x Note whatever is expected to be recorded among readings including the
procedure.
x Note the variables given
x Draw a table of results in column form
x You may ask for a graph paper and start on labeling axes and writing the title of
the graph required.
(b)
During the process of carrying out the experiment.
x Divide the 2 hours by 2 hence on average use 1 hour to complete all the
procedures involved.
x A student should have obtained results after 30 or 35 minutes such that the
remaining 25 minutes is for completing other procedures.
x Start by assembling all the apparatus as indicated in the diagram with all the
scales of the instruments facing you.
x Follow the procedures step by step as you observe and note all what is supposed
to be recorded.
(c)
Presentation of the results
The following steps should be followed while presenting the results:x Start by writing the aim of the experiment.
x Follow the instructions sequentially noting down the readings at every stage.
x Enter the results in a suitable table (this should be in column form), the results for
a particular variable are filled from top to bottom.
(d)
How to draw a table of results
x Every column should have it's variable plus the unit of the variable separated using
a forward slash ( / ) e.g if mass m is given in kg, then m is a variable and kg is a
Unit.
x We write it at the top of the column as m / kg.
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1.8
Derived quantities.
The derived quantities are quantities obtained after multiplication or division of
fundamental quantities. They should also have their corresponding units.
E.g Period T/s squared it should be ࢀ૛ /࢙૛
(a)
The product
If you are asked to tabulate the values e.g ‫ݑ‬, ‫ݒ‬ǡ Ƭ‫ݒݑ‬, and if the Figures are big we
consider three significant Figures or one decimal place but if the Figures are not big
record to at least 3 decimal places.
One may
ͳ ͳ ͳ ܸ
ǡ ǡ ǡ
‫ܫ ݒ ݑ‬
‫ܫ‬
be
required
to
record
in
the
table,
values
of
say;
and so on, record to three decimal places of correctly rounded off values.
The unit for that column is obtained by applying a simple mathematical substitution
e.g
(i) if we have ‫ݔ‬Ȁܿ݉ and‫ݕ‬Ȁܿ݉. Then ‫ ݕݔ‬becomes ‫ݕݔ‬Ȁܿ݉ ʹ ,
and
‫ݔ‬
‫ݕ‬
as
‫ݔ‬
‫ݕ‬
ͳ
as / ܿ݉ െͳ
‫ݔ‬
(no units since it is a ratio)
(ii) ForܸȀ‫ݒ‬, ‫ܫ‬Ȁ‫ ܣ‬,
(b)
ͳ
‫ݔ‬
ͳ
‫ܫ‬
ܸ
‫ܫ‬
/‫ܣ‬െͳ and becomes
ܸ
‫ܫ‬
/ ܸ‫ܣ‬െͳ or (&Ugrave;)
Sum and Difference
If the given quantities are ‫ݔ‬ǡ ‫ݕ‬ǡ ‫ ݒ‬measured in centimeters, then the values of ‫ ݔ‬൅
‫ݕ‬ǡ ‫ ݑ‬൅ ‫ݒ‬ǡ ‫ݑ‬Ȃ ‫ݒ‬ǡ ‫ݔ‬Ȃ ‫ݕ‬ǡ are recorded according to the number of decimal places and
the unit remains centimeters(cm).
(c)
Sine, Cosine and their reciprocals
The sine of angle i, cosine of angle i, and their reciprocals are recorded to three decimal
places. Remember trigonometric ratios of an angle have no units.
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SAMPLE QUESTION
In this experiment you will determine acceleration due to gravity, g using a spiral
spring.
(a)
Arrange the apparatus as shown in Figure 1 above.
(b)
Attach a pointer to the spring
(c)
Read the initial position ‫ Ͳݕ‬of the pointer on the metre rule.
(d)
Suspend a mass m= 0.10kg from the table.
(e)
Record the new position ‫ ݕ‬of the pointer
(f)
Displace the mass m through a small vertical distance and release it to oscillate.
(g)
Measure and record the time, t ,for 20 oscillations.
(h)
Calculate the period, T.
(i)
Repeat procedures (d) to (h) for values of m = 0.20, 0.30, 0.040 and 0.50kg
(j)
Record your results in a suitable table including values of ݀ ൌ ‫ݕ‬Ȃ‫ Ͳݕ‬and ܶ ʹ
(k)
Plot a graph of m (on the vertical axis) against T2 (along the horizontal axis)
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FORMAT FOR THE ANSWER SHEET LAYOUT.
An experiment to determine acceleration due to gravity, g using spiral spring.
Note: Values recorded are assumed values for illustration
(c) ‫ Ͳݕ‬ൌ ͳʹǤͷܿ݉
(1 decimal place for a ruler)
(e)
When m = 0.10kg
y = 15.3 cm (1 decimal place)
(g)
t = 15.5s
(stop clock)
( 1 decimal place)
or t = 15.40s
(stop watch)
(2 decimal places)
‫ݐ‬
ܶ ൌ ቀ ቁ
ʹͲ
ൌ ͳͷǤͷ
ʹͲ
s
= 0.775s ( 3 decimal places)
(j) Table of results
Here the variables are ‫ Ͳݕ‬ǡ ‫ݕ‬ǡ ݉ǡ ‫ݐ‬ǡ ܶܽ݊݀݀.
For the 1st column we record values of the variable as it is given in the question paper
plus their units and the number of decimal places and after the last entry the table should
be closed.
m/kg
‫ Ͳݕ‬Ȁܿ݉
‫ݕ‬Ȁܿ݉
݀Ȁܿ݉
‫ݐ‬Ȁ‫ݏ‬
ܶȀ‫ݏ‬
ܶ ʹ Ȁܵ ʹ
0.10
0.20
0.30
0.40
0.50
After table of results you may be required to draw a graph and analyze your results.
How to draw a graph
(i)
Put a title on the graph but do not include the units.
(ii) Draw the axes of the graph and label them with the corresponding variables but
include the units.
(iii) Choose a convenient scale that covers at least three-quarters (&frac34;) of the graph
paper
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The graph.
Consider a sample table of result shown below
݉Ȁ݇݃
‫ݐ‬Ȁ‫ݏ‬
ܶ ʹ Ȁܵ ʹ
ܶȀ‫ݏ‬
0.10
7.0
0.35
0.12
0.20
9.5
0.48
0.23
0.30
12.0
0.60
0.36
0.40
14.5
0.73
0.53
How to find a scale
An A4 graph paper can have; vertically 10 or 11 divisions of 10 small squares each and
on the horizontal seven or eight divisions each of 10 small squares
Vertically:
Total No. of small squares = 10 x 10
= (100 small squares)
Suitable values for scale (i) real numbers 1, 2, 4, 5, &laquo;HWFDQGWKHLUPXOWLSOHV
(ii)
for
smaller
values
we
mostly
consider
0.001, 0.01, 0.1, 0.002, 0.02, 0.2, 0.005, 0.05, 0.5 etc
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e.g
Rough value = greatest vertical point for plotting
100
=
ͲǤͶ
ͳͲͲ
=0.004kg (since this value is among our suitable values and rounded to one
real number then this is our vertical scale)
Horizontally
Total No. of small squares = 8 x 10
= (80 small squares)
Rough value = greatest horizontal point for plotting
80
=
ͲǤͷ͵
ͺͲ
=0.006625(here we round off to one real value to get the scale)
=0.007(this would be the scale but it is not among the suitable values)
Therefore the suitable value for the scale will be 0.008࢙૛
Using the scales to plot points
Horizontal point,
૙Ǥ૚૛
=15 small squares
૙Ǥ૙૙ૡ
૙Ǥ૜૟
૙Ǥ૙૙ૡ
ൌ45 small squares
vertically point
૙Ǥ૚
ൌ 25 small squares
૙Ǥ૙૙૝
૙Ǥ૜
= 75 small squares
૙Ǥ૙૙૝
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Full Illustration on a real graph paper
Points to note about a graph
x Starting point.
If the values are so close to zero (0) then our starting value will be zero (0)
otherwise the starting value is not necessarily zero.
Each axis should have its own starting point
x Plot points using either an encircled dot
pencil..
or a cross
&sup3;x&acute;
using a sharp HB
x Draw the line of best fit, if it is a straight line use a transparent ruler or join points
with a free hand if it is a curve.
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x A line of best fit is a line that passes through most of the points and leaves out
almost the same number of points below and above the line.
x Draw a triangle of slope or gradient that covers all the plotted points and touches
none of the plotted points.
Note
If it is a straight line you may be required to obtain the slope, the intercept or the
relationship between the two quantities.
Intercept
An intercept is the value of the other variable when the other assumes, a zero value
e.g if ‫ ݕ‬ൌ ݉‫ ݔ‬൅ ܿ, then when x = 0, y = c. c is called the y &plusmn; intercept.
Note: when asked to find the y- intercept the x- axis MUST begin from zero.
Slope
To find a slope draw a triangle that covers all the plotted points and read the coordinates
where triangle of slope meets the line of best fit.
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݄ܶ݁‫ ݕܾ݊݁ݒ݅݃ݏ݅݁݌݋݈ݏ‬ൌ
Hence here S =
    
   
ο‫ܯ‬
οܶ ʹ
‫ܤܣ‬ሺ݇݃ ሻ
S=
‫ܥܤ‬ሺ‫ ʹ ݏ‬ሻ
‫ܤܣ‬
S=
‫ܥܤ‬
kg‫ ݏ‬െʹ
Note: The slope value should have units that correspond to the units of the substituted
values. From above AB has the Unit of kg, BC has the Unit of ‫ ʹ ݏ‬Ǥ
Therefore S has XQLWV&para; kg‫ ݏ‬െʹ
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CHAPTER
TWO
MECHANICS
EXPERIMENTS
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EXPERIMENT 01
In this experiment you will determine the mass of the metre rule provided
Fig 1
(a)
Place the block of wood on the table so that it rests on its smallest cross sectional
area.
(b)
Place the knife edge on top of the block
(c)
Balance the metre rule provided on the knife edge with its calibrated face upwards
(d)
Record the position C at which the metre rule balances
(e)
Suspend a 100 g mass at the 2 cm mark and adjust the rule until it balances again.
(f)
Determine the distances ݈ͳ and ݈ʹ of C and the weight respectively from the knife
edge
(g)
Repeat procedures (e) and (f) with the weight hanging from the 6, 10, 14, 18 and
22 cm marks respectively.
(h)
Record your results in a suitable table
(i)
Plot a graph of ݈ͳ against ݈ʹ
(j)
Find the slope s, of your graph.
(k)
Calculate the mass, M, from the expression
21
M ൌ 100s
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EXPERIMENT 02
In this experiment you will determine the density, &ntilde; , of the rubber provided
(a)
Record the mass, M, of the metre rule provided.
Fig. 2
(b)
Suspend the rubber bung, W, at a distance d = 5 cm from the zero end of the
metre rule.
(c)
Balance the metre rule with its graduated face upwards on the knife edge as
shown in Figure 2.
(d)
Measure and record the distances, d1 and d2, of the knife edge from the zero and
100 cm marks of the metre rule respectively.
(e)
Repeat procedures, (b) to (d) for values of d equal to 10, 15, 20, 25 and 30 cm.
(f)
Tabulate your results, including values of ሺ݀ʹ Ȃ݀ͳ ሻܽ݊݀ሺ݀ͳ Ȃ ݀ሻǤ
(g)
Plot a graph of ሺ݀ʹ Ȃ݀ͳ ሻ against ሺ݀ͳ Ȃ ݀ሻǤ
(h)
Find the slope, S, of your graph
(i)
Determine the density, &ntilde; ,of rubber from the expression
22
&ntilde; = 0.5 S.
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EXPERIMENT 03
In this experiment, you will determine the weight WQ of the rubber bung Q
provided
(a)
Balance the metre rule provided on a knife edge.
(b)
Note the position P of the knife edge where the metre rule balances and record its
distance ࢞૙ from the end B.
Fig. 3(a)
(c )
Place a mass M = 20 g at the 10.0 cm mark and adjust the position of the knife
edge until the metre rule balances again as shown in Figure 3(a).
(d)
Measure and record the distances࢞૚ and ࢞૛
(e)
Calculate the weight ܹ of metre rule from the expression
(f)
Remove the mass M.
(g)
Place the knife edge on the wooden block provided.
Fig. 3(b)
23
ܹൌ
ͲǤʹ‫ͳ ݔ‬
‫ ʹ ݔ‬െ‫Ͳ ݔ‬
3+&lt;6,&amp;6(;3(5,0(176
(h)
Suspend the rubber bung Q at a distance d = 5.0 cm from the zero end of the
metre rule.
(i)
Adjust the metre rule on the knife edge until it balances as shown in Figure 3(b).
(j)
Measure and record the distances x and y.
(k)
Repeat procedures (h) to (j) for values of d = 15.0 cm, 25.0 cm, 35.0 cm and
45.0cm.
(l)
Record your results in a suitable table including values of ‫ݔ‬Ȃ ‫ݕ݀݊ܽݕ‬Ȃ ݀.
(m)
Plot a graph of ‫ݔ‬Ȃ ‫ ݕ‬against ‫ݕ‬Ȃ ݀
(n)
Find the slope S of the graph
(o)
Calculate the weight WQ of the rubber bung from the expression: ܹܳ
24
ൌ ܹܵ
ʹ
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 04
In this experiment, you will determine the mass, m2 of the sand provided.
Fig. 4
(a)
Suspend a metre rule from a retort stand using a piece of thread provided.
(b)
Adjust the position of the thread until the metre rule balances horizontally.
(c)
Read the record the position, G of the thread on the metre rule.
(d)
Suspend a mass, m1 = 100 g at a distance, d1 = 20 cm from one end of the metre
rule.
(e)
Suspend the mass, m2 of the sand from the opposite side of the thread of
suspension.
(f)
Adjust the position of the mass m2 until the metre rule balances again as shown in
Figure 4.
(g)
Measure and record the distance, d2 of the point of suspension of mass m2 from
the point G.
(h)
Repeat procedures (d) to (g) for values of m1 = 200, 300, 400, 500 and 600g.
(i)
Calculate the distance, d3 of m1 from G.
(j)
Enter your results in a suitable table including values of m1d3.
(k)
Plot a graph of m1d3 against d2.
(l)
Determine the slope, m2 of the graph.
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EXPERIMENT 05
In this experiment, you will determine the relative density , &ntilde; , of the material of
solid X provided.
Fig. 5
(a)
Record the mass, M of the solid, X provided.
(b)
Suspend a metre rule from a clamp using a piece of thread.
(c)
Adjust the metre rule until it balances horizontally.
(d)
Read and record the distance of the balance point, P, of the rule from
(e)
Suspend the solid, X at a distance d = 10 cm from end A of the metre rule.
(f)
Immerse solid X completely in water in the mug.
(g)
Suspend a 100 g mass from a point, Q, between P and B
(h)
Adjust the position of Q until the metre rule balances horizontally, with X
completely immersed and not touching the mug as shown in Figure 5.
(i)
Measure and record distance z, and y.
(j)
Repeat procedure (e) to (i) for values of d = 15, 20, 25, 30 and 35 cm.
(k)
Enter your results in a suitable table.
(l)
Plot a graph of z against y.
(m)
Find the slope, S of the graph.
(n)
Calculate the relative density, &ntilde;, of the material from the expression.
&ntilde; ൌ
‫ܯ‬
‫ܯ‬െͳͲͲܵ
26
end A.
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 06
In this experiment, you will determine the mass of the metre rule provided .
Fig. 6(a)
(a)
Fig.6 (b)
Balance the metre rule provided on a knife edge with its calibrated face upwards
as shown in Figure 6(a)
(b)
Record the distance݈‫ ݋‬of the knife edge from the 0െcm mark of the metre rule.
(c)
Place the 50g mass on the metre rule at a point x = 5 cm as shown in
Figure 6
(b) above and move the rule until it again balances horizontally.
(d)
Record distance y.
(e)
Repeat procedures (c) and (d) for values of x = 10, 20, 25 and 30 cm
(f)
Record your results in a suitable table.
(g)
Plot a graph of y against x.
(h)
Find the slope s, of your graph
(i)
Calculate the mass M0 of the metre rule from the expression:
‫݋ܯ‬
ൌ ͷͲሺͳെܵሻ
ܵ
(j)
From the graph, find the value of y when x = 0 and call it ‫݋ݕ‬
(k)
Calculate
݇
the
value
of
the
constant
ͷͲ‫Ͳݕ‬
Ͳ െ‫Ͳݕ‬
ൌ݈
27
k
from
the
expression
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT07
In this experiment you will determine the centre of gravity, C, and mass m of a
metre rule.
(a) Balance the metre rule on knife edge until it balances horizontally.
(b) Note the balance point P,
Fig. 7
(c)
Hang a 50g mass M at the 5.0 cm mark from end A
(d)
Balance the meter rule on a knife edge until it balances horizontally.
(e)
Note the distance Y of the new balance point from end B
(f)
Repeat the procedures (c) to (e) for masses of 100g, 150g, 200g and 250g.
(g)
(h)
Plot a graph of Y against M
(i)
Determine the Y - intercept C on the graph
(j)
Determine the slope S of the graph
(k)
From the graph find the value of M for Y = ‫ͳݕ‬
Where ‫ ͳݕ‬ൌ
ͻͷ൅‫ܥ‬
ʹ
28
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT08
In this experiment you will determine the mass of a metre rule provided.
Fig. 8
point G.
(a)
Balance the metre rule provided on a knife edge and mark the balance
(b)
Arrange the apparatus a shown in Figure 8.
(c)
Place the knife edge at a distance y = 10 cm from G.
(d)
Starting with M = 40g adjust the position of the mass until the metre rule balances
horizontally.
(e)
Measure and record X, the distance of M from the knife-edge.
(f)
Repeat procedures (c) to (e) for value of M =60g, 80g, 100g and 120g.
(g)
Record your results in suitable table including values of
(h)
ͳ
Plot a graph of M (along vertical axis) against . (along horizontal axis)
ࢄ
(i)
Find the slope, s.
(j)
Calculate the mass of the metre rule K from the expression K = 0.10s.
29
ͳ
ࢄ
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 09
In this experiment, you will determine the acceleration due to gravity.
(a)
Clamp the spring provided and a metre rule as shown in Figure 9 below.
Fig. 9
(b)
Read and record the position of the pointer on the metre rule.
(c)
Suspend a mass M = 0.200 kg from the spring.
(d)
Read and record the new position of the pointer.
(e)
Find the extension, x, of the spring in metres
(f)
Pull the mass vertically down wards through a small distance and then
release it to oscillate.
(g)
Determine the time, t, for 20 oscillations
(h)
Find the time, T, for one oscillation.
(i)
Repeat procedures (c) to (h) for values of M = 0.300, 0.400, 0.500, 0.600 and
0.700 kg
(j)
(k)
Record your results in a suitable table, including values of T2.
Plot a graph of T2 (along the vertical axis) against x (along the horizontal
axis).
(l)
Find the slope S, of the graph
(m)
Calculate the acceleration due to gravity, g, from the expression
30
ࡿൌ
Ͷ&eth;ʹ
݃
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT10
In this experiment you will determine the acceleration due to gravity, g, using a
simple pendulum.
Fig. 10
(a)
Tie the thread firmly to the pendulum bob and set it up as a pendulum by
clamping the thread firmly between two wooden blocks.
(b)
Adjust the point of support to be exactly 120 cm above the floor.
(c)
Make the value of x = 20 cm as shown in Figure 10
(d)
Set the bob in a small horizontal oscillation and measure time t for 20 complete
oscillations.
(e)
Find time T, for one oscillation
(f)
Repeat procedure (c) to (e) for values of x = 40, 60, 80, 100cm
(g)
Tabulate your results in a suitable table including values of T2 and
࢟ ൌ ሺͳʹͲȂ ‫ݔ‬ሻ
(h)
Plot a graph of T2 against ‫ ݕ‬and find the gradient K of the graph.
(i)
Calculate the value of acceleration due to gravity, g, from the expression.
݃ൌ
Ͷ&eth;ʹ
݇
31
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 11
In this experiment you will determine the length, ࢒૙ of a pendulum using two
methods.
Method 1
Fig. 11
(a) Suspend the given pendulum from a retort stand.
(b) Displace the pendulum bob through a distance x = 15.0 cm as shown in
11.
(c) Measure and record the vertical displacement y of the bob.
(d) Repeat procedure (b) and (c ) for x = 20.0, 25.0, 30.0, 35.0 and 40.0 cm
(e) Record your values in a suitable table including values of x2
(f) Plot a graph of x2 against y.
(g) Find the slope, s, of the graph
(h) Calculate the length of the pendulum ݈Ͳ from
݈Ͳൌ࢙
૛
32
Figure
3+&lt;6,&amp;6(;3(5,0(176
Method II
(a) Displace the pendulum bob through a small angle and release it.
(b) Measure the time taken for the pendulum to make 20 oscillations.
(c) Find the period, T, of the pendulum.
(d) Calculate the length of the pendulum,݈Ͳ , from
࢒૙ = 24.5 T2.
33
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 12
In this experiment you will determine the thickness, t, of the coin provided
(a) Arrange the apparatus as shown in Figure 12
Fig. 12
3
(b)Measure out volume, V = 10cm of water using a measuring cylinder and pour it into
the clamped boiling tube.
(c) Drop the coin provided into the boiling tube
(d) Measure and record the depth, h, of the water in the boiling tube
(e) Repeat procedures (b) to (d) for V = 15, 20, 25, 30 and 35 cm3
(f) Record your results in a suitable table
(g) Plot a graph of h against V
(h) Determine the intercept, h0 on the h &plusmn; axis
(i) Determine the slope, s, of the graph
(j) Calculate the thickness, t, from the expression :
‫ݐ‬ൌ
ͲǤʹͶ݄ Ͳ
‫ݏ‬
34
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT13
In this experiment you will determine YRXQJ&para;VPRGXOXVIRUZRRG.
Fig.13
(a)
Measure and record the thickness, d, of the metre rule.
(b)
Clamp the metre rule provided with the graduated face upwards such that the free
length equals 80cm as shown in Figure 13 above.
(c)
Attach a mass M equal to 0.05kg at the end of the metre rule with a rubber band
(d)
Depress the mass through a small vertical distance and release it to oscillate
(e)
Measure and record the time for 20 oscillations. Find the period T.
(f)
Repeat the procedures (c) to (e) for M equal to 0.10, 0.15, 0.20, 0.25 and 0.30kg.
(g)
Record your results in a suitable table including values of T2
(h)
Plot a graph of T2 (along the vertical axis) against M (along the horizontal
axis).
(i)
Find the slope, S, of the graph
(j)
Calculate YouQJ&para;VPRGXOXV&lt;IRUZRRGIURP
Y=
ͳͷͻͲ
ܵ݀ ͵
35
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 14
In this experiment you are to determine the mass of the boiling tube provided.
PART I
(a) Measure the length L0 of the test tube in cm.
(b) Wind the wire 10 times round the boiling tube, making sure the windings are close
together.
Fig. 14(a)
(c) Measure the length L of the 10 turns of wire used.
(d) Find D from the expression ‫ ܦ‬ൌ ͲǤͲ͵‫ܮ‬
(e) Calculate ܸͳ ൌ ͲǤ͹ͻ‫Ͳܮ ʹ ܦ‬
PART II
(a)
Clamp the boiling tube vertically such that the bottom touches the base of the
retort stand as shown in the Figure 14(b) below.
Fig. 14(b)
36
3+&lt;6,&amp;6(;3(5,0(176
(b)
3
Measure 20cm of water and pour into the tube, measure and record the height, h,
of the water level from the base of the retort stand.
(c)
Repeat procedure (b) for volumes of water V = 30, 35, 40, 45 and 50 cm3
(d)
Tabulate your results in a suitable table.
(e)
Plot a graph of V ( along the vertical) against h (along the horizontal axis)
(f)
Find the slope, s, of the graph
(g)
From your graph, find the value V2 of V when, h, is equal to the length L0 of the
boiling tube
(h)
Find the value of ࢓ ൌ ૛Ǥ ૟ሺࢂ૚ Ȃࢂ૛ ሻ
37
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 15
In this experiment you will determine the mass of a metre rule provided.
Fig. 15
(a)
Place the knife-edge underneath the 5cm mark of the metre rule provided.
(b)
Tie a piece of thread at the 95cm mark of the metre rule and suspend the metre
rule from the spring balance.
(c)
Adjust the position of the clamp so that the metre rule is horizontal.
(d)
Place a 0.10kg mass at x = 0.10m from the knife-edge.
(e)
Record the reading, W, on the spring balance.
(f)
Repeat procedures (c ) and (e) for values of x = 0.15, 0.20, 0.25 and 0.30m.
(g)
Plot a graph of W against x
(h)
Find the intercept‫ܫ‬, on the W axis.
(i)
Find the intercept of ‫ ܫ‬on the W axis.
(k)
Calculate the mass of the metre rule, M, from ‫ ܯ‬ൌ ͲǤʹ‫ܫ‬
38
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 16
In this experiment you will investigate the relationship between the depression of a
loaded beam and the distance between the supports.
(a)
Attach a pointer at the 50 cm mark of the rule provided.
(b)
Place the metre rule so that it lies horizontally on the two knife edges provided
(c)
Clamp a scale vertically and place it near the 50 cm mark of the metre rule as
shown in Figure16.
Fig. 16
(d)
Adjust the knife edges such that the distance, d, between them is equal to 40 cm
and they are equidistant from the 50 cm mark of the metre &plusmn; rule
(e)
Read and record the position of the pointer, ܺͲ on the metre &plusmn; rule
(f)
Suspend a mass of 500g at the 50 cm mark of the metre - rule.
(g)
Read and record the position of the pointer on the scale.
Hence find the depression, x, of the metre &plusmn; rule at its mid-point.
(h)
Remove the mass from the metre - rule.
(i)
Repeat procedures (d) to (h) for values of d equal to 50, 60, 70, 80 and 90 cm.
(j)
Record your results in a suitable table including the values of ‫ ܏ܗܔ‬૚૙ ࢞ and
‫ ܏ܗܔ‬૚૙ ࢊ
39
3+&lt;6,&amp;6(;3(5,0(176
(k)
Plot a graph of ‫ ܏ܗܔ‬૚૙ ࢞ሺalong the vertical axis) against ‫ ܏ܗܔ‬૚૙ ࢊ (along the
horizontal axis).
(l)
Find slope, n, of the graph.
40
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 17
In this experiment you will determine the density of liquid provided
(a)
Record the radius, r, of the small beaker ( or can) provided
Fig. 17
(b)
Place the small beaker into the large beaker containing water.
(c)
Add small quantities of sand gradually into the small beaker until the beaker floats
upright in the water as shown in Figure 17. Make sure the small beaker does not
touch the sides of the large beaker.
(d)
Place 3 bottle tops into the small beaker
(e)
5HDGDQGUHFRUGWKHGHSWK&sup3;K&acute;E\ZKLFKWKHVPDOOEHDNHUVLQNV
(f)
Repeat procedure (d) and (e) for 6, 9, 12 and 15 bottle tops.
(g)
Record your results in a suitable table.
(h)
Plot a graph of number of bottle tops against, h.
(i)
)LQGWKHVORSV&sup3;s&acute;RIWKHJUDSK
(j)
Calculate the density to water &ntilde;, from the expression ૛Ǥ ૞࢙ ൌ &ntilde;Sr2
41
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 18
In this experiment you will determine the ratio of densities of the liquids provided.
(a)
Place the masses provided on the hanger.
(b)
Pass the thread over the pulley and attach the hanger at its end as shown in Figure
18.
Fig. 18
(c)
Adjust the number of masses on the hanger so that the hanger and piece of wood
balance without dipping in water.
(d)
Lower the piece of wood so that its lower end just touches the water in the beaker.
(e)
Read and record the position of the bottom of the piece of wood on the mm scale.
(f)
Remove a mass, m of 10g from the mass hanger. Read and record the position of
the bottom of the wood on the mm scale again.
(g)
Find the depth, h of the bottom of the wood below the water surface.
(h)
Repeat procedures (f) and (g) for m =20, 30, 40, 50 and 60g
(i)
Enter your values in a suitable table
42
3+&lt;6,&amp;6(;3(5,0(176
(j)
Pot a graph of m ( along the vertical axis) against h ( along the horizontal axis).
(k)
Find the slops S1 of the graph
(l)
Pour out the water and dry the beaker
(m)
Transfer the liquid marked L into the beaker
(n)
Repeat procedures (c ) to (i) using liquid, L.
(o)
Plot a graph of m (along the vertical axis) against h (along the horizontal axis)
(p)
Find the slope, S2, of this graph
(q)
Find the values of
࢙૛
࢙૚
43
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 19
In this experiment, you will determine the force constant, K, of the spiral spring
provided.
Fig. 19
(a)
Suspend the spring with a pointer fixed at its free end from a clamp.
(b)
Place one end of the metre - rule against a brick and suspend the other end from
the spring using a piece of thread as shown in Figure 19.
(c)
Adjust the thread such that height, h, above the table is equal to 30.0cm.
(d)
Measure and record the distance, ݈‫( ݋‬in metres) between the end of the metre rule
pressing against the brick.
(e)
Clamp a half metre rule vertically with its graduated face against the end of the
pointer.
(f)
Note and record the position of the pointer.
(g)
Place a mass, 100g at a distance, d, of 20.0cm from the end of the metre rule
pressing against the brick.
(h)
Read and record the new position of the pointer
44
3+&lt;6,&amp;6(;3(5,0(176
(i)
Find the extension, x, of the spring.
(j)
Repeat procedure (g) to (i) for values of , d, equal to 30.0, 40.0, 50.0, 60.0 and
70.0 cm.
(k)
Record your results in a suitable table.
(i)
Plot a graph of x against d.
(m)
Find the slope, s, of your graph and the intercept, c, on the vertical axis.
(n)
Calculate the constant, K, from
K ൌ 45
ͲǤͻͺ
‫Ͳ ݈ݏ‬
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 20
In this experiment, you will determine the constant, K, of a helical spring.
Fig. 20
(a)
Tie firmly the piece of block of wood provided to the base of the stand using
knitting thread labeled, T1, such that the face with the nail faces upwards.
(b)
Tie one end of helical spring to the nail using a small piece of thread labeled, T2.
(c)
Tie one end of thread, T3, to the free end of the helical spring and attach the
optical pin to act as a pointer.
(d)
Pass the free end of T3, over the pulley and tie it to a 0.70kg mass as shown in
Figure 20.
(e)
Adjust the arrangement such that the spring is vertical.
(f)
Read and record the initial position, P0, of the pointer on the metre rule scale.
(g)
Remove a mass, m = 0.10kg from the hanger.
(h)
Read and record the new position of the pointer, ࡼ૚ , on the scale.
(i)
Find the depression, e, of the spring in metres.
(j)
Repeat procedures (g) to (i) for values of m = 0.20, 0.30, 0.40, 0.50 and 0.60kg.
46
3+&lt;6,&amp;6(;3(5,0(176
(k)
Record your results in a suitable table.
(l)
Plot a graph of m (along the vertical axis) against e ( along the horizontal axis).
(m)
Determine the slope, S, of the graph
(n)
Calculate the constant, K, from
ࡷ ൌ ૚૙ࡿ
47
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 21
In this experiment, you will determine the co-efficient of static friction,P, between
the surface of a metre rule and a soda bottle top.
Fig. 21
D
Tie a loop of thread at one end of metre rule labeled, M.
E
Place the other end of the metre rule against the base of a brick/block lying on
the surface of a table.
F
Put the soda bottle top on the metre rule such that the distance, x, from base of the
brick/block to the middle of the bottle top is 10 cm.
G
Pass the free end of the thread over the rod.
H
Gently raise the end, P, of the metre rule by pulling the thread downwards until
the bottle top just moves (make sure the string is vertical at all times) as shown in
Figure 21.
I
Tie the thread round the rod in order to keep the metre rule in position.
J
Measure and record the vertical height, h, of the initial position of the bottle top
from the table.
K
Repeat procedures (b) to (g) for values of x,= 20, 30, 40, 50 and 60cm
48
3+&lt;6,&amp;6(;3(5,0(176
L
Record your results in a suitable table including values of ሺ࢞ ൅ ࢎሻǡ ൫࢞Ȃ ࢎ൯ǡ
ሺ࢞ ൅ ࢎሻሺ࢞Ȃ ࢎሻࢇ࢔ࢊටሺ࢞ ൅ ࢎሻሺ࢞Ȃ ࢎሻǤ
M
Plot a graph of, ࢎ (along the vertical axis) against ටሺ࢞ ൅ ࢎሻሺ࢞Ȃ ࢎሻ (along
the horizontal axis).
N
Find slope,P, of the graph
49
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 22
In this experiment you will determine a constant, k, of the spiral spring provided
PART A
(a) Wrap firmly the trip of paper provided three times round the spiral spring.
(b) Mark on the paper the point where the third wrapping ends.
(c) Remove the paper
(d) Measure the length, x, of the paper corresponding to the three turns.
Fig. 22(a)
(e) Measure and record the un stretched length l of the spring as in Figure 22(a)
(f) Find the value of, q, from ‫ݍ‬
ൌ ͵͸ SL
‫ʹݔ‬
Fig.22 (b)
50
3+&lt;6,&amp;6(;3(5,0(176
(a) Clamp the two pieces of wood with one free end of the spring between them as
shown in Figure 22 (b).
(b) Fix a pointer at the free end of the spring using a little plasticine.
(c) Note and record the position, P0, of the pointer against a metre rule.
(d) Suspend a mass m = 600 g from the spring
(e) Remove a mass of 100 g from the hanger
(f) Note and record the new position, p, of the pointer
(g) Find the change, y = p &plusmn; p0 in the position of the pointer
(h) Repeat procedures (e) to (g) until there is no mass suspended from the spring.
(i) Record your values in a suitable table.
(j) Plot a graph of, y, (along the vertical axis) against, m (along the horizontal axis)
(k) Find the slope, s, of the graph.
(l) Calculate the constant ,k, from
k=
ͲǤͻͺࢗ
࢙
51
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 23
In this experiment, you will determine the acceleration due to gravity, g.
Fig.23
(a)
Clamp a metre rule horizontally at the 50 cm &plusmn; mark with the scale facing you.
(b)
Tie the two pieces of thread provided to the pendulum bob.
(c)
Tie the free ends of threads onto the metre rule such that the lengthǡ ݈ǡ of each
thread is 0.60 m, as shown in Figure 23.
(d)
Adjust the distance, a, between the two loops to 0.10m.
(e)
Pull slightly the bob towards you and release it to oscillate
(f)
Measure and record the time for twenty oscillations.
(g)
Find the period, T.
(h)
Repeat procedures (d) to (g) for a = 0.20, 0.30, 0.40, 0.50 and 0.60 m.
(i)
Record your results in a suitable table including values of T2 and a2.
52
3+&lt;6,&amp;6(;3(5,0(176
(j)
2
2
Plot a graph of T (along the vertical axis) against a ( along the horizontal
axis).
(k)
Find the slope, S, of the graph.
(l)
Calculate g , from
g =
െ&eth;ʹ
ͳǤʹܵ
53
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 24
In this experiment you will determine the coefficient of static friction,P, between
two surfaces.
Fig. 24
(a)
Fix the manila sheet (with a scale attached on) using pieces of cello tape on a
table.
(b)
Record the mass, M0 of the wooden block
(c)
Attach the spring to the block using a short piece of thread.
(d)
Place the wooden block on the manila sheet, such that the spring lies along the
scale as shown in Figure 24.
(e)
Place a mass, M1 = 0.200kg on the wooden bock.
(f)
Adjust the position of the spring such that the string is taut
(g)
Read and record the position, P1 of the un stretched spring
(h)
Gently pull the spring while observing the block until the block just moves over
the manila sheet.(Make sure the block does not come in contact with the scale).
(i)
Record the new position of the spring P2 when the block just moves.
(j)
Determine the extension e = P2 &plusmn; P1 (in meters) of the spring.
(k)
Repeat procedures (e) to (j) for M1 = 0.300, 0.400, 0.500, 0.600 and 0.700 kg.
(l)
Record your results in a suitable table including values of (M0 + M1).
(m)
Plot a graph of e ( along the vertical axis) against (M0 + M1) ( along the
horizontal axis)
54
3+&lt;6,&amp;6(;3(5,0(176
(n)
Determine the slope, S, of the graph
(o)
Find
the
coefficient
of
static
ࡿ ൌ ૙Ǥ ૜૜P
55
friction,
P
from
the
expression
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 25
In this experiment, you will determine the effective mass, m0, of the spring
provided.
Fig. 25
(a) Attach an optical pin to one end of the spring to act as a pointer.
(b) Clamp vertically the spring as shown in Figure 25.
(c) Clamp a metre rule vertically beside the spring with the zero mark up.
(d) Read and record the position, P0, of the pointer on the metre rule.
(e) Suspend a mass, m = 0.10kg from the free end of the spring.
(f) Read and record the new position, P1, of the pointer.
(g) Find the extension, e = P1 &plusmn; P0 of the spring.
(h) Remove the rule.
(i) Displace the mass slightly downwards and release it to oscillate.
(j) Measure and record the time for 20 oscillations.
(k) Determine the time T, for one oscillation.
(l) Repeat procedures (i) to (k) for values of m = 0.20, 0.30, 0.40 and 0.50kg.
(m)
Record your results in a suitable table including values of T2
(n) Plot a graph of T2 (along the vertical axis) against m (along the horizontal axis).
56
3+&lt;6,&amp;6(;3(5,0(176
2
(o) Find the intercept, C, on the T &plusmn; axis.
(p) Calculate the effective mass, m0, of the spring from the expression.
࢓૙ ൌ
࡯ ࢍ
૝૙ &eth;૛ ࢋ (Where gൌ 10݉‫ ݏ‬െ2 and ߨ ൌ 3Ǥ14 )
57
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 26
In this experiment, you will determine the relative density of liquid, L, provided.
Fig. 26
(a) Clamp the metre rule vertically.
(b) Suspend the spring with a pointer beside the metre rule.
(c) Suspend the spring with a pointer using knitting thread, as shown in Figure 26.
(d) Record the initial position, P, of the pointer on the metre rule.
(e) Pour 50cm3 of water into the beaker and record the new position of the pointer.
(f) Find the extension, y, produced.
(g) Repeat procedures (e) and (f) for 100, 150, 200 and 250cm3 of water.
(h) Remove the beaker, empty and dry it.
(i) Repeat procedures (c) to (g), using liquid, L. Call the extensions produced, x
(j) Record your results in a suitable table.
(k) Plot a graph of y (along vertical axis) against x (along horizontal axis).
(l) Determine the slope, S, of the graph
(m)
Calculate relative density from the expression: Relative density =
58
૚
ࡿ
3+&lt;6,&amp;6(;3(5,0(176
CHAPTER THREE
OPTICS
EXPERIMENTS
59
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EXPERIMENT27
In this experiment we will investigate the relationship between the number of
images formed by two mirrors inclined to each other and the angle between the two
mirrors.
(a)
Draw two lines such that they make an angle ߠ= 900 at the point of intersection as
shown in the Figure 27 below
Fig. 27
(b)
Place mirror A and B as shown above on the lines.
(c)
Place an optical pin a distance of about 6 cm in front of the point of intersection of
the two mirrors.
(d)
Count and record the number n of the images observed. (Place the eye a distance
of more than half a metre away from the mirrors).
(e)
Keeping mirror A on the line repeat procedure (c) and (d) adjusting the position of
B such that it makes angles ߠ of 720, 600, 400 and 300.
(f)
Enter your results in a suitable table including values of
(g)
Plot a graph of n against
(h)
Find the intercept, C, on the n &plusmn; axis.
(i)
Find the slope S of the graph.
ͳ
ߠ
60
ͳ
ߠ
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 28
In this experiment, you will determine the relationship between the angle of
rotation of the mirror and supplement of the angle of deviation of incident ray.
Fig. 28
(a) Fix a white sheet of paper on a board using drawing pins.
(b) Draw a line AB, 10 cm long and about 6 cm from the bottom of the white sheet of
paper.
(c) Draw a line AB1, making an angle of 100 with AB.
(d) Draw lines AB2, AB3, AB4 AB5 and AB6 such that the lines make angles of ߠ ൌ200,
300, 400, 500 and 600 respectively.
(e) Mark off point O on AB such that AO = 4 cm.
(f) Draw a line DOF such that angle DOB is 1000
(g) Place the mirror provided along AB and fix it in place using plasticine.
(h) Fix pins at P1 and P2 on the line DO as shown in Figure 28.
(i) Fix a pin at P3 such that it appears in line with the images of the first two pins as seen
through the mirror.
(j) Remove the mirror.
(k) Join OP3
(l) Measure and record angle, ࢻ = DOP3
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(m)
Repeat procedures (g) to (k) with the mirror placed along AB1, AB2, AB3, AB4,
AB5 and AB6 respectively. Keep P1 and P2 fixed in their positions.
(n) Measure and record the corresponding values of ࢻ
(o) Enter your results in a suitable table.
(p) Plot a graph of ߠ against ࢻ
(q) Determine the slope, s, of your graph
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EXPERIMENT 29
In this experiment, you will determine the focal length, f, of the concave mirror
provided.
Fig. 29
(a)
Connect the electrical circuit for lighting the bulb.
(b)
Arrange the illuminated wire gauze, the concave mirror and the white screen as
shown in Figure 29.
(c)
Move the concave mirror so that it is a distance, u = 15 cm from the object.
(d)
Adjust the position of the white screen until a sharply focused image, I. of the
object appears on it.
(e)
Measure and record the image distance, v.
(f)
Repeat procedures (c) to (e) for values of u = 20, 25, 30, 35 and 40 cm.
(g)
Enter your results in a suitable table including values of ‫ ݒݑ‬and ሺ‫ ݑ‬൅ ‫ݒ‬ሻ.
(h)
Plot a graph of ሺ‫ ݑ‬൅ ‫ݒ‬ሻ (along the vertical axis) against ‫(ݒݑ‬along the
horizontal axis).
(i)
Find the slope, S, of the graph
(j)
Calculate
fൌ
the
focal
length,
૚
࢙
63
f,
from
the
expression
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT30
In this experiment you will determine the focal length f, of a concave mirror
Fig. 30
(a)
Arrange the concave mirror and the illuminated wire gauze such that their centres
are at the same height above the bench and lie in a straight line as shown in
Figure30
(b)
Place the mirror at a distance, u, equal to 80.0 cm from the illuminated wire
gauze.
(c)
Place the screen between the wire gauze and the mirror such that a sharp image of
the wire gauze is formed on the screen. The screen must be slightly displaced
from the straight line between the centres of the mirror and the wire gauze.
(d)
Measure the distance, v, of the screen from the mirror.
(e)
Repeat procedures (b) to (d) for values of u = 70.0, 60.0, 40.0 and 30.0 cm
(f)
Record your results in a suitable table.
(g)
Plot a graph of v (along the vertical axis) against
axis).
(h)
Find the slope, S, of the graph.
(i)
Find the value, t, of v when /u = 0.
(j)
Calculate the focal length, f, of the mirror from
v
fൌ ሺ‫ ݏ‬൅ ‫ݐ‬ሻȀʹ
64
v
/u (along the horizontal
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT31
In this experiment, you will determine the focal length of the converging lens
provided
(a)
Mount the lens in the holder provided and place it facing a window.
(b)
Place a white screen behind the lens.
(c )
Adjust the position of the white screen until a clear image of a distant object is
obtained.
(d)
Measure and record the distance, f, between the lens and the white screen.
(e)
Connect the bulb, the dry cells and switch, K in series.
(f)
Arrange the bulb, wire gauze, lens and the white screen as shown in Figure 31
below.
Fig. 31
(g)
Adjust the lens so that the distance, x, between the wire gauze and the lens is
equal to 2.0f.
(h)
Close switch, K, and move the white screen until a clear image of the wire gauze
is obtained on the white screen.
(i)
Measure and record the distance, y between the lens and the white screen.
(j)
Open the switch, K
(k)
Repeat procedures (g) to (j) for values of x = 2.4f, 2.8f, 3.2f and 3.6f
(l)
Record your results in a suitable table including values of ‫ݕݔ‬andሺ࢞ ൅ ࢟ሻ
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(m)
Plot a graph of ‫ ( ݕݔ‬along the vertical axis) against ሺ࢞ ൅ ࢟ሻ ( along the
horizontal axis).
(n)
Determine the slope, F, of the graph, where, F, is the focal length of the lens.
(o)
Find the value of ࡲെࢌ
ࢌ
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EXPERIMENT32
In this experiment, you will determine the focal length, of the converging lens
provided.
Fig. 32
(a)
Fix the lens in the lens holder provided.
(b)
Switch on the bulb to illuminate the wire gauze
(c)
Adjust the position of the screen so that it is at a distance, ‫ = ݕ‬90 cm from the
gauze.
(d)
Place the lens between the gauze and the screen such that it is near the gauze.
(e)
Adjust the position of lens to obtain a clear image of the gauze on the screen as
shown in Figure 32.
(f)
Measure and record the distance ࢒૚ of the lens from the gauze.
(g)
Keeping the gauze and screen fixed, move the lens toward the screen to obtain a
diminished image on the screen.
(h)
Measure and record the distance ࢒૛ of the lens from the gauze.
(i)
Find the distance x = ࢒૛ &plusmn; ࢒૚ .
(j)
Repeat procedures (c) to (i) for values of ‫ = ݕ‬85.0, 80.0. 75.0, 70.0 and 65.0cm.
(k)
Record your results in a suitable table including values of 67
࢞૛
࢟
3+&lt;6,&amp;6(;3(5,0(176
࢞૛
(l)
Plot a graph of y against
(m)
Find the intercept, c on the y &plusmn; axis of the graph
(n)
Calculate the focal length, f, from the expression
࢟
68
fൌ
࡯
4
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT33
In this experiment you are to find the focal length, f 0 , of a converging lens
provided.
(a)
Focus a distant object, such as a window, on a screen.
(b)
Measure and record the distance, f, between the lens and the screen.
Fig. 33
(c)
Set up the lens with the illuminated object on one side of it and the screen on the
other as shown in Figure 33 above.
(d)
Make the object distance u = 4f and adjust the position of the screen until a sharp
image is obtained.
(e)
Measure and record the image distance v
(f)
Repeat procedure (c ) to (e) for u = 3 f, 3 f, 2 f, 2 f and 1
(g)
Tabulate your results in a suitable table including values of
(h)
Plot a graph
(i)
Read and record the value, u0 of
(j)
Read and record the value v0 of
(k)
૚
ࢁ
of against
1
1
1
2
2
2
૚
ࢂ
૚
૚
ࢂ
when
૚
૚
૛
ࢁ૙
Calculate the value of ࢌ૙ ൌ ቀ
૚
when
ࢁ
૚
૚
ࢁ
൅ ቁ
ࢂ૙
69
= 0
ࢂ
=0
૚
ࢁ
f.
૚
and ࢂ
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT34
In this experiment, you will determine the focal length of a converging lens.
(a)
Place the lens facing a window with the screen behind it, then adjust the position
of the screen until a sharp image of a distant object is focused on it.
(b)
Measure and record distance, x, between the lens and the screen.
(c)
Arrange a lit bulb and the screen such that the distance, d, between them is
slightly greater than 4‫ ݔ‬.
(d)
Measure and record the distance, d.
Fig. 34
(e)
Place the lens between the bulb and the screen as shown in Figure 34.
(f)
Adjust the position of the lens to obtain a clearly focused magnified image of the
bulb on the screen.
(g)
Measure and record the distance y1, between the bulb and the lens.
(h)
Displace the lens towards the screen so as obtain a clearly focused diminished
image of the bulb on the screen.
(i)
Measure and record the distance y2 between the bulb and the lens.
(j)
Repeat procedures (c ) to (i) for values of; d + 5, d + 10, d + 15, d + 20 and
d + 25 cm
(k)
Record your results in a suitable table including values of y2 &plusmn; y1 , ( y2 &plusmn; y1 )2, d2
and [ d2 - (y2 &plusmn; y1)2].
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3+&lt;6,&amp;6(;3(5,0(176
(l)
2
2
Plot a graph of [d &plusmn; ( y2 &plusmn; y1) ] ( along the vertical axis) against d
(a long the horizontal axis).
(m)
Find the slope, s, of the graph
(n)
Calculate the focal length, f, of the lens from the expression s = 4f.
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EXPERIMENT35
In this experiment you will determine the focal length, f, of a converging lens.
(a)
Arrange the apparatus so that the lens is between a distant object and a screen.
(b)
Adjust the screen to obtain a sharp image of the distant object. Measure and
record distance x between the lens and screen.
(c)
Arrange the apparatus as shown in Figure 35 below with distance U = 6.0x.
Fig. 35
(d) Close switch k and adjust the screen to obtain a sharp image of the wire gauze.
Open the switch. Measure and record distance v.
(e) Repeat procedure (d) for the other values of u = 5.0x, 4.0x, 3.0x, 2.0x and 1.5x.
(f) Record your values in suitable table including values of
(g) Plot a graph of
ࢂ
ࢁ
ࢂ
.
ࢁ
(along the vertical axis) against v (along the horizontal
axis).
(h) Determine the slope, S of your graph.
(i) Calculate the value of, f, from the expression; f
72
=
૚
ࡿ
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 36
In this experiment, you will determine the focal length of a diverging lens using
converging lens.
Fig. 36
(a)
Align the screen, lens L1 and the illuminated wire gauze such that the centres of
the lens and the gauze are at the same height above the bench and lie in a straight
line as shown in Figure 36.
(b)
Place the illuminated wire gauze at a distance P = 20 cm from lens L1.
(c)
Close switch, K.
(d)
Adjust the position of the white screen to obtain a sharp image of the wire gauze
on it.
(e)
Measure and record the distance, V1 of the screen from lens, L1.
(f)
Place the diverging lens, L2 (between L1 and the illuminated wire gauze) at a
distance x = 8 cm from lens, L1 ensuring that its centre is in line with that of L1.
(g)
Keeping the distance, P, the same, adjust the position of the white screen until a
sharp image is again formed on it.
(h)
Measure and record the distance, V, of the white screen from L2.
(i)
Repeat procedures (f) to (h) for values of x = 9, 10, 11, 12 and 13 cm.
73
3+&lt;6,&amp;6(;3(5,0(176
1
(j)
Tabulate your results including values of U = (V &plusmn; x), VU and ( V &plusmn; U ).
(k)
Plot a graph of (V &plusmn; U) ( along the vertical axis) against UV (along the
horizontal axis).
(l)
Find the slope, S, of the graph
(m)
Calculate the focal length, f, of the diverging lens L2 from
fൌ
ͳ
ܵ
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EXPERIMENT37
In this experiment, you will determine the refractive index, n, of the material of the
glass block provided.
Fig 37
(a)
Fix the plane sheet of paper on a soft board using drawing pins.
(b)
Place the glass block on the sheet of paper so that it rests on its broad face and
trace its outline ABCD.
(c)
Remove the glass block
(d)
At point, O, about 2cm from A draw a line RO at an angle ߠ= 800 to AB
(e)
Fix pins P1 and P2 along RO and then replace the glass block onto its outline.
(f)
Looking through side DC, fix pins P3 and P4 such that they appear to be in a
straight line with the images of P1 and P2 as shown in Figure 37.
(g)
Remove the pins and the glass block and draw a line through P3 and P4 to meet
DC at P.
(h)
Join P to O.
(i)
Measure angle ߙ.
75
3+&lt;6,&amp;6(;3(5,0(176
0
(j)
Repeat procedures (d) to (i) for ߠ= 70, 60, 50, 40, and 30
(k)
Record your results in a suitable table including values of cos ߠand cos ߙ
(l)
Plot a graph of cos ߠ(along vertical axis) against cos ߙ(along horizontal axis).
(m)
Find the slope, n, of the graph.
76
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EXPERIMENT38
In this experiment, you will determine the refractive index n of the material of the
glass block provided.
Fig. 38
(a) Fix the plane sheet of paper on a soft board using drawing pins.
(b) Place the glass block on the sheet of paper so that it rests with its board face and trace
its outline ABCD.
(c) Remove the glass block
(d) Draw a normal MN to cut AD and BC at P and N respectively, such that AP is 2cm.
(e) Draw OP such that the angle i= 300
(f) Fix pins P1 and P2 vertically along OP
(g) Replace the glass block onto its outline
(h) While looking from side BC, fix pins P3 and P4 so that they appear to be in straight
line with the images of P1 and P2 as shown in Figure 38.
(i) Remove the glass block
(j) Draw a line RQ through P3 to P4 meet BC at Q.
(k) Join Q to P and measure PQ. Call it y.
(l) Produce RQ to meet the normal MN at S.
77
3+&lt;6,&amp;6(;3(5,0(176
(m)
Measure the distance QS. Call it x.
(n) Repeat procedures (e) to (m) for values of i = 400, 500, 600 and 700.
(o) Record your results in a suitable table.
(p) Plot a graph of y against x
(q) Find the slope n of the graph.
78
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EXPERIMENT39
In this experiment you ware to determine the path of the emergent ray.
(a) Place the white sheet of paper on the soft board
(b) Fix the white paper onto the soft board using drawing pins.
Fig. 39
(c) Trace the glass block
(d) Remove the glass block
(e) Mark a point K on AB such that AK = 1.0cm. Through K draw a line perpendicular
to AB to cut KN at N
(f) Measure ‫ܮ‬0 ǡthe length of KN
(g) Mark point P on DC such that DP= 3.0cm. Mark also points Q, R, S, T and U at
equal intervals of 1.0cm. Replace the glass block.
(h) Fix a pin vertically at point K in contact with the edge of the block. Fix a second pin
vertically at point P. Looking through the glass block from the side CD, fix a third
79
3+&lt;6,&amp;6(;3(5,0(176
pin L such that pins L and P appear to be in line with the image of pin K seen
through the glass block.
(i) Remove the block and join LP and produce it to cut the line KN at T. Join KP also.
(j) Measure and record lengths X and Y. Such that X = TP and Y = KP.
(k) Keeping the first pin fixed at K, repeat the experiment with the second pin at the
positions Q, R, S, T and U.
(l) Record your results in a suitable table.
(m)
Plot a graph of Y against X , From your graph find X when Y = ‫ Ͳܮ‬Ǥ
80
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT40
In this experiment, you will determine the refractive index of the glass block
provided.
Fig. 40
D
Fix a white sheet of paper on a soft board by means of drawing pins
E
Place the glass block on the white paper with the broad face topmost
F
Trace the outline of the block.
G
Remove the glass block and then label its outline ABCD as shown in
Figure 40.
H
With point N midway between A and B, draw a line ON making an angle ݅ = 300
with AB.
I
Fix pins P1 and P2 vertically along ON.
J
Place the glass block on its outline
K
Looking through the glass block from side DC, fix pins P3 and P4 such that they
appear to be in line with images of P1 and P2.
81
3+&lt;6,&amp;6(;3(5,0(176
L
Remove the glass block and the pins.
M
Draw a line through the positions of P3 and P4 to meet DC at M.
N
Join N to M.
O
Draw a circle of radius 4.5 cm with its centre at N.
P
Draw a perpendicular to AB from a point where the circle cuts line ON. Measure
and record distance y.
Q
Draw another perpendicular to AB from a point where the circle cuts line NM.
Measure and record distance x.
R
Repeat procedures (e) to (n) for values of ݅ = 400, 500, 600, 700 and 800.
S
Record your results in a suitable table.
T
Plot a graph of y against x.
U
Find the slope, &THORN; of the graph.
82
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EXPERIMENT41
In this experiment you are required to determine the refractive index, n, of, the
glass prism provided.
(a)
Place the glass prism on the soft board on the plane sheet of paper and draw the
outline. Label the vertex ABC as shown in Figure 41
Fig. 41
(b)
At point N, 2 cm from a vertex B, draw a normal to the line AB
(c)
Draw a line DN at angle of incidence ݅ 0 = 300
(d)
Stick pins P1 and P2 about 10cm apart on line DN
(e)
Place the prism back on the paper with its faces exactly marching with lines and
vertex as in (a) above. View image of pins P1 and P2, along the face BC
(f)
Stick pins P3 and P4 about 10cm apart such that pins P3 and P4 are collinear with
the images of pins P1 and P2
(g)
Remove the pins and the prism. Draw a line through the mark of pins P 3 and P4
and join point x to point N. measure and record angle ‫ Ͳ ݎ‬.
(h)
Repeat procedures (c) to (g) for values of angle ݅ Ͳ ൌ 400, 500, 600, 700.
(i)
Tabulate your results in suitable table including values of sin݅ Ͳ and sin ‫Ͳ ݎ‬
(j)
Plot a graph of sin ݅ Ͳ ( along the vertical axis) against sin‫( Ͳ ݎ‬along the
horizontal axis).
(k)
Find the slope, n of your graph.
83
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CHAPTER FOUR
HEAT
EXPERIMENTS
84
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT42
In this experiment, you will determine the rate of cooling, R, of a body.
(a)
Pour 300ml of water in the beaker provided
(b)
Heat the water until it boils.
(c)
Place a thermometer in the beaker of boiling water. Read and record the steady
temperature, to of the water.
(d)
Remove the thermometer and immediately start the stop clock.
(e)
While holding the thermometer in air, record the reading, T, of the thermometer at
half-minute intervals for five minutes.
Record the results in a suitable table
(g)
Plot a graph of temperature, T, against time, t.
(h)
Determine the time, t1 taken for the temperature to fall from 450C to 300C.
(i)
Calculate R from R =
െ
૚૞
࢚૚
85
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 43
In this experiment you will determine the rate of cooling, K, of water.
(a)
Read and record the room temperature, ࣂ૙
(b)
Measure 100ml of water and pour it into the beaker provided.
(c)
Heat the water in the beaker until it boils.
(d)
Transfer quickly the boiling water into the calorimeter.
(e)
Place a thermometer into the hot water in the calorimeter.
(f)
Start the clock when the temperature reaches 700C.
(g)
While stirring, record the temperature, ࣂ, of the water in the calorimeter every
two minutes, until the temperature reaches 400C.
(h)
Record your results in a suitable table including values of (ࣂ െ ࣂ૙ ).
(i)
Plot a graph of (ࣂ െ ࣂ૙ ) (along vertical axis) against time, t (along horizontal
axis).
(j)
Read and record the value of (ࣂ െ ࣂ૙ ) at t = 15 minutes.
(k)
Draw a tangent to the graph at t = 15 minutes.
(l)
Find the slope, k of the tangent.
86
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 44
In this experiment you will determine the cooling constant, L of water.
(a)
Record the room temperatureࣂ
(b)
Heat 100cm3 of water in the beaker until it boils.
(c)
Transfer the hot water quickly into the calorimeter
(d)
Place the thermometer in hot water and start the stop clock/watch when
temperature of the water is 700C.
(e)
Record the temperature ࣂ࢚ of the water after every two minutes for 14 minutes.
(f)
Record your results in a suitable table including values of (ࣂ࢚ െ ࣂ) and
࢒࢕ࢍ૚૙ ሺࣂ࢚ െ ࣂሻ
(g)
Plot a graph of࢒࢕ࢍ૚૙ ሺࣂ࢚ െ ࣂሻ (along vertical axis) against time, t (along the
horizontal axis).
(h)
Find the slope, s, of the graph
(i)
Calculate the cooling constant, L, from the expression s = - 26.06L.
87
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT45
In this experiment, you will compare the rates of cooling of a body under different
external conditions.
(a)
Heat the water in the beaker provided and leave it to boil.
(b)
Wrap the given piece of duplicating paper around the bulb of the thermometer use
the rubber bands to hold the paper in place.
(c)
Place the thermometer inside a dry test tube.
(d)
Place the test tube in boiling water
MAKE SURE THAT WATER DOES NOT ENTER THE TEST TUBE.
Leave the test tube in boiling water until the thermometer indicates a steady
temperature.
(e)
Remove the thermometer and immediately start the stop clock
(f)
While holding the thermometer in air, record the reading of the thermometer at
one-minute intervals for 15 minutes.
(g)
Place the wrapped thermometer, directly into boiling water. Leave the
thermometer in the boiling water until it indicates a steady temperature.
(h)
Repeat procedures (e) and (f), but this time record the reading of the thermometer
at half-minute intervals for 5 minutes.
(i)
Record your results in a suitable table.
(j)
Using the same axes, plot a graph of temperature (along the vertical axis)
against time ( along the horizontal axis) for the results obtained in
(k)
For each graph, determine the time taken for the temperature to fall from
to 400C.
(l)
(f) and (h).
Find the ratio of the two times obtained in (k) above.
88
600C
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT46
In this experiment you will determine the rate of loss of heat of a rubber bung at a
specified temperature.
(a)
Record the mass m of the rubber bung provided in kilograms.
(b)
Tie one end of the piece of thread provided onto the rubber bung
(c)
Place the rubber bung inside the beaker containing water such that the loose end
of the thread hangs outside the beaker.
(d)
Heat the water in the beaker until it boils for at least 10 minutes.
(e)
Measure out 120 cm3 of cold water and pour it into a 200 cm3 beaker
(f)
Measure and record the initial temperature of the cold water.
(g)
Transfer the rubber bung from the boiling water to the water in the 200 cm3
beaker and start the stop-clock at the same time.
(h)
Measure and record in a suitable table the temperature of the water after every
minute for 10 minutes
(STIR THE WATER ALL THE TIME WITH THE THERMOMETER)
(i)
Plot a graph of temperature of the water against time.
(j)
Determine the slope, s, of your graph at a point corresponding to a time of 2
minutes.
(k)
Find the value of the rate of loss of heat.
Q = 1.7 x 103ms
89
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EXPERIMENT47
In this experiment you will determine the cooling constant, ࢻ, of water
(a) While holding a thermometer with the bulb in air (away from the heating source),
read and record the room temperatureߠ0
(b) Pour 100 cm3 of boiling water into the calorimeter.
(c) Insert the thermometer into the calorimeter containing hot water
(d) Start the stop watch/stop clock when the temperature ߠͲ reaches 700c.
(e) Record the temperature ߠͲ of the water in the calorimeter after every time
interval, t, of 2 minutes for 14 minutes.
(f) Record your results in a suitable table including values of (ࣂ െ ߠͲ )
(g) Plot a graph of ࢒࢕ࢍ૚૙ (ࣂ െ ߠͲ ) against t.
(h) Find the slope, S, of the graph
(i) Calculate the cooling constant, ࢻfrom the expression ࢻ ൌ
90
࢙
ߠͲ
3+&lt;6,&amp;6(;3(5,0(176
CHAPTER FIVE
ELECTRICITY
EXPERIMENTS
91
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EXPERIMENT48
In this experiment you will determine the resistance,&Oacute;, of the bare wire, W,
provided.
Fig. 48
D
Connect the ammeter A, switch K, dry cell E, and wire W, as shown in
Figure
48.
E
Adjust distance, l, of the wire to 20 cm.
F
Close the switch, K, and record the reading, I, of the ammeter.
G
Repeat procedures (b) and (c) for values of l equal to 30, 40, 50, 60, 70 and 80 cm.
H
Record your results in a suitable table including the values of 1ൗࡵ
I
Plot a graph of
J
Determine the slope, S, of your graph
K
Calculate the resistivity, &ntilde;ǡof the wire from &ntilde; ൌ 1Ǥ6 ൈ 10
1ൗ against l.
ࡵ
െ5
92
ܵ
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT49
In this experiment, you will determine the ratio, P, of the internal resistance of a
pair of dry cells to the resistance per centimeter of the wire labeled, W.
Fig. 49
(a)
Fix the bare wire labeled, W, on the bench using cello tape.
(b)
Connect the circuit as shown in Figure 49.
(c)
Starting with a length, l=20cm, read and record the voltmeter reading, V0.
(d)
Close switch, K.
(e)
(f)
Open switch, K.
(g)
Repeat procedures (c) to (f) for values of l= 30, 40, 50, 60 and 70 cm.
(h)
Record your results in a suitable table including values of
ܸ ൌ ሾܸ0 െ ܸͳ ሿ and ࢂ૚
࢒
ࢂ૚
(i)
Plot a graph of V against
(j)
Determine the slope, P, of the graph.
࢒
93
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EXPERIMENT50
In this experiment, you will determine the constant, L 0, of the bicycle spoke.
Fig. 50
(a)
Connect the circuit shown in Figure 50.
(b)
Starting with a length, X = 0.800 m, close the switch, K.
And record the ammeter reading, l.
(c)
Open the switch, K.
(d)
Repeat procedures (b) to (d) for values of X = 0.700, 0.600, 0.500, 0.400 and
0.300 m.
(e)
Record your results in a suitable table including values of 1ൗࡵ
(f)
Plot a graph of ͳൗࡵ(along the vertical axis) against X
(along the
horizontal axis).
(g)
Find the slope, S, of the graph.
(h)
Read and record the intercept, C, on the ͳൗࡵ axis.
(i)
Calculate the value of ࡸ૙ from the expression
94
ܵൌ
2‫ܥ‬
‫ܮ‬0
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT51
In this experiment you will determine the internal resistances of a dry cell provided
(a) Stretch and fix wire P on to the table with a cello tape.
(b) Connect the dry cell, 5&Ugrave; resistor and a Voltmeter as shown in Figures 51.
Fig. 51
(c)
3ODFHWKHMRFNH\RQWKHZLUH3VXFKWKDWƐ is equal to 30 cm. Record the
(d)
5HSHDW SURFHGXUH F DERYH IRU YDOXHV RI Ɛ HTXDO WR FP FP FP FP
80cm and respectively.
(e)
Record your results in a suitable table including values of ƐൗV
(f)
Plot a graph of
(g)
Find the slope s of the graph.
(h)
Find the value n of /V when L = 0cm.
(i)
Calculate the e.m.f E of the dry cell from
κൗ (on vertical axis) against Ɛ(on horizontal axis).
Ɛ
ࡱ ൌ
(j)
െ૛
૜ൈ૚૙
ࡿ
Calculate the internal resistance r of the dry cell from r ൌ 2݊‫ ܧ‬െ 1
95
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT52
In this experiment, you will determine the internal resistance, r , of the cells
provided.
(a)
Record the resistance RS of the resistor R.
(b)
Connect the two dry cells in series across the Voltmeter and record the reading V0
of the Voltmeter.
(c)
Fix the bare wire P provided on the bench using cello tape.
Fig. 52
(d)
Connect the circuit as shown in Figure 52, starting with a length
x = 0.200 m.
(e)
Close switch K.
(f)
Record the reading I of the ammeter
(g)
Open switch K.
(h)
Repeat procedures (d) to (g) for values of x = 0.300, 0.400, 0.500, 0.600 and
0.700 m.
૚ൗ and ૚ൗ
࢞
ࡵ
(i)
Record your results in a suitable table including values of
(j)
Plot a graph of ૚ൗࡵ
(k)
Find the intercept C on the ૚ൗ࢞ &plusmn; axis.
(l)
Calculate the internal resistance r from the expression ‫ ݎ‬ൌ ܸ‫ ܥ ݋‬െ ܴ‫ݏ‬
against ૚ൗ࢞
96
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EXPERIMENT53
In this experiment you will determine the e.m.f, E and internal resistance, r, of the
cell provided.
Fig. 53
(a)
Fix the bare wire, W, on the table using cello tape
(b)
Connect the circuit shown in Figure 53 with l, about 95cm.
(c)
Close the switch, K.
(d)
Adjust the crocodile clip at, P, until the ammeter reading I = 0.30A.
(e)
(f)
Open switch, K.
(g)
Repeat procedures (c) to (f) for I = 0.35, 0.40, 0.45, 0.50 and 0.55A.
(h)
Record your reading in a suitable table including values of ૚ൗࢂ and ૚ൗ࢒
(i)
Plot a graph of ૚ൗࢂ (along the vertical axis) against ૚ൗ࢒ (along the horizontal
axis).
(j)
Find the slope, S, of the graph.
(k)
Find the intercept, C, on the ૚ൗࢂaxis.
(l)
Calculate E from ࡱ ൌ ૚ൗ࡯
(m)
Findǡ ࢘ from S
‫ݎܥ‬
= 3Ǥ15
97
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EXPERIMENT 54
In this experiment you will determine the resistance per metre, q, of the bare wire
provided.
(a)
Fix the bare wire, W, on the bench using pieces of cello tape.
Fig. 54
(b)
Connect the dry cells, a torch bulb, a voltmeter V, an ammeter A, a switch K and
the bare wire W as shown in Figure 54.
(c)
Starting with length l = 1.00m, close the switch, K.
(d)
(e)
Repeat the procedures (c) and (d) for l = 0.80, 0.60, 0.40 and 0.20 m
(f)
Tabulate your results, including values of x0 =Il
(g)
Plot a graph of V (along the vertical axis) against x0 (along the horizontal axis).
(h)
Determine the slope, S, of the graph
(i)
Find q = - S.
98
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT55
In this experiment, you will determine the diameter, d, of the bare wire provided.
Fig. 55
D Fix the bare wire on the table using cello tape.
E Set up the circuit as shown in Figure 55.
F Adjust the position of the crocodile clips such that l = 0.85 m.
G Close the switch, K,
I Open switch, K.
J Repeat procedures (b) to (e) for value of l = 0.75, 0.65, 0.55, 0.45 and 0.35 m.
K Enter your results in a suitable table including values of ૚ൗ࢒ and ૚ൗࢂ .
L Plot a graph of ૚ൗ࢒ against ૚ൗࢂ
M Find the slope, s, of the graph.
N Calculate the diameter of the bare wire, d, from the expression;
݀ ൌ 7Ǥ90ൈ10െ4
1
ܵ ൗ2
99
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT 56
In this experiment you will determine the internal resistance, r, of two cells in
series.
PART 1
Fig. 56(a)
(a) Connect the circuit shown in Figure 56(a) with resistance R1 = 2.0
(c) Close switch, K.
(e) Open switch, K.
(f) Calculate, ‫ݎ‬1 from
‫ݎ‬1 ൌ
ሺܸ0 െܸ1 ሻ
‫ܫ‬1
PART II
Fig. 56(b)
100
3+&lt;6,&amp;6(;3(5,0(176
(a) Disconnect crocodile clips P and Q, from R 1 in the circuit in Figure 56(a).
(b) Fix the bare wire labeled W, on the table using cello tape.
(c) Connect crocodile clips P and Q to the bare wire as shown in Figure 56(b).
(d) Adjust the length, l, to 1.00m.
(e) Close switch, K.
(g) Repeat the procedures (d) to (g) for the values of l = 0.90, 0.80, 0.70 and 0.60m.
(h) Open switch, K.
(i) Record your results in a suitable table.
(j) Plot a graph of V (along the vertical axis) against I (along the horizontal axis).
(k) Determine the slope, S, of the graph.
(l) Find, r2 from; r2 = െS.
(m)
Calculate the mean value,
‫ݎ‬ǡ‫ݎ‬1 ‫ݎ‬2 Ǥ
101
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT57
In this experiment, you will determine a constant, ᢥǡ of the bare wire, W, provided.
(a)
(b)
Record the diameter, d, of the bare wire provided.
Calculate the constant, ᢥfromᢥ
ൌ
݀2
4
Fig. 57
(c)
Fix the bare wire, W, provided on the meter rule using cello tape.
(d)
Connect the circuit as shown in Figure 57.
(e)
Starting with length l = 0.200m, close switch, K.
(f)
Read and record the readings V and I of the voltmeter and ammeter respectively.
(g)
Open switch, K.
(h)
Repeat procedures (e) to (g) for values of l = 0.300, 0.400, 0.500, 0.600 and
0.700m.
(i)
Tabulate your results in a suitable table including values of ࢂൗࡵ
(j)
Plot a graph of ࢂൗࡵ(along the vertical axis) against length l (along the
horizontal axis).
(k)
Find the slope, S, of your graph
(l)
Find the constant, ݊, of the bare wire, W, from ᢥ ൌ
102
44ൈ10
‫ݏ‬
െ8
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT58
In this experiment you will determine the internal resistance of the cells provided
(a)
Arrange the apparatus as shown in Figure 58
Fig. 58
(b)
Move the Jockey along the bare wire, W until the ammeter reading
I = 0.30 A. Read and record the corresponding voltmeter reading V
(c)
Repeat procedure (b) for values of I = 0.40, 0.50, 0.60, 0.70, 0.80 and 0.90A
(d)
Record your results in a suitable table
(e)
Plot a graph of V against I
(f)
Determine the intercept V0 on the V &plusmn; axis and I0 on the I &plusmn; axis
(g)
Find the value of, r, from the expression
r ൌ
ࢂ૙
ࡵ૙
103
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT59
In this experiment you will determine the resistance per meter of the wire.
Fig. 59
Connect the circuit as shown in Figure 59
(a)
Adjust the length L to 0.10m
(b)
Close the switch K
(c)
Record the voltmeter and ammeter readings V and I respectively
(d)
Repeat procedures (b) to (d) for values of L equal to 0.30, 0.50, 0.70 and
0.90m
(e)
Tabulate your results including values of
(f)
Plot a graph of
(g)
Determine the slope, S, of the graph.
(h)
Read and record the value of
ࢂ
ࡵ
ࢂ
ࡵ
against L
ࢂ
ࡵ
when L = 0
104
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EXPERIMENT60
In this experiment, you will determine the resistance, s, of the filament of the torch
bulb provided.
(a) Fix the bare wire P, on the bench using pieces of cello tape
(b) Connect the circuit as shown in Figure 60.
Fig. 60
(c) Starting with length x0 = 1.00 m and x = 0.20 m, close the switch K.
(e) Open the switch, K.
(f) Repeat procedures (b) to (e) for values of x = 0.30, 0.40, 0.50, 0.60 and
0.70 m.
(g) Record your results in a suitable table.
(h) Plot a graph of V (along the vertical axis) against I (along the horizontal axis).
(i) Determine the slope, s, of the graph.
105
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EXPERIMENT61
In this experiment you will determine the resistance of a resistor.
(a) Connect the dry cells, resistance wire, resistor, R, voltmeter V and ammeter A as
shown in Figure 61.
Fig. 61
(b) Adjust the length, y, of the resistance wire to 20cm.
(c) Close switch K and record the reading V of the voltmeter and I of the ammeter.
Open switch K.
(d) Repeat procedures (b) to (c) for values of y equal to 30, 40, 50, 60 and
(e) Record your results in a suitable table.
(f) Plot a graph of V against I.
(g) Find the slope, s, of the graph.
106
70 cm.
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT62
In this experiment you are to determine the internal resistance of two cells in series.
Fig. 62
(a)
Connect the circuit as shown in Figure 62.
(b)
Starting with l = 20cm, close the switch S read and record values of V and I of the
voltmeter and ammeter respectively.
(c)
Open switch S.
(d)
Repeat the procedures in (b) and (c) for l = 30, 40, 50, 60 and 70 cm.
(e)
Record your results in a suitable table.
(f)
Plot a graph of V against I.
(g)
Determine the intercept V0 on the V &plusmn;axis and intercept I0 on the I &plusmn;axis.
(h)
Calculate C from the expression
Cൌ
ࢂ૙
ࡵ૙
107
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EXPERIMENT63
In this experiment you will determine the resistance of a resistance wire.
(a)
Fix the resistance wire provided firmly on the bench.
(b)
Connect the circuit as shown in Figure 63 with the length PQ = 20 cm.
Fig. 63
(c)
Adjust the rheostat so that the ammeter reading I = 0.6 A.
(d)
Connect a voltmeter across the cells and record its reading V 1.
(e)
Disconnect the voltmeter and connect it across PQ. Record its reading V 2.
(i)
Repeat procedures (c), (d) and (e) for values of I ൌ 0.5, 0.4, 0.3, 0.2 and 0.1A.
(g)
Record your results in a suitable table
(h)
On the same axes, plot a graph of
(i)V1 (along the vertical axis) against I (along the horizontal axis).
(ii)V2 (along the vertical axis) against I (along the horizontal axis).
(FOR THE HORIZONTAL AXIS USE A SCALE OF 1 CM TO 0.1 A)
(i)
Read the values of current ‫ܫ‬
(j)
Calculate the value of
0
and voltage ܸ 0 where the two graphs meet.
ܸ0
‫ܫ‬0
108
3+&lt;6,&amp;6(;3(5,0(176
EXPERIMENT64
In this experiment you will determine the current through torch bulbs when its
resistance is equal to that of a given resistor.
(a)
Record the resistances, R of the resistor Q provided.
(b)
Connect the dry cells, the switch K, the rheostats, S, resistor P and the resistor Q
in series.
Fig. 64
(c)
Connect the voltmeter across the resistor Q.
(d)
Close switch K and adjust the rheostat until the reading V 1 of the voltmeter is
0.80V.
(e)
Disconnect the voltmeter across resistor Q and connect it across the resistor P.
(f)
Record the reading V2 of the voltmeter.
(g)
Repeat procedures (c) to (g) for 0.85V, 0.90V, 0.95V and 1.00V.
(h)
Record your results in a suitable table.
(i)
Plot a graph of V1 (along the vertical axis) against V2 (along the horizontal
axis).
(j)
Using the same axes, draw the line V1ൌV2.
(k)
Record the values, V0 of V2 at the point of intersection of the line with the graph.
(l)
Find the value I of the current through the resistor P from the expression
I=
ܸ0
ܳ
109
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EXPERIMENT 65
In this experiment you are required to find the resistance in parallel.
(a)
Connect up the circuit as shown in Figure 65;
Fig. 65
(b)
Starting with crocodile clip P not making contact with the wire XY, close the
switch, read and record the current I.
(c)
Clip the crocodile clip on the wire XY with L ൌ 90.
(d)
Read and record the new current I.
(e)
Repeat procedures (c) to (d) for values of Lൌ70, 60, 50, 40cm.
(f)
(g)
Plot a graph of I against
(h)
Find the value of I when Lൌ
ࡵ
ࡸ
૚
૛
CP
110
‫ܫ‬
‫ܮ‬
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