# Physics form four mid term exam 2023

```FORM FOUR MIDTERM EXAMINATION APRIL
2023
PHYSICS
TIME: 3:00 Hours
April, 2023
INSTRUCTIONS:
i.
ii.
iii.
This paper consists of sections A, B and C with total of ten (10) questions.
Answer all questions in section A, B and C.
All working should be in blue or black ink except drawings which must be in pencil.
iv.
Where necessary, the following constant may be used:
 Acceleration due to gravity g= 10m/s2
 S.T.P, 760mmHg, 273K
 Heat capacity of Aluminium C = 23.062J/K
Pie π = 3.14
v.
QUESTION NUMBER
FOR EXAMINERS USE
ONLY
SCORE
1
2
3
4
5
6
7
8
9
10
11
Page 1 of 6
EXAMINERS INITIALS
SECTION A (16 Marks)
1. For each of items (i)-(x) choose the correct answer from among the given alternatives and
write its letter in the answer sheets provided.
i. The multiple reflection of the sound produced when it travels in an enclosed room
refers as:
A. Sound waves
C. Transverse waves
B. Resonance D. Echo E. Reverberation
ii. The phenomenon that causes the dispersion white light into spectrum prism:
A. Refraction B. Deflation
B. Reflection D. absorption E. Interference.
iii. The death of deep seas creatures is when brought shallow water. This happens
because of:
A. Their pressure inside bodies is greater to the surrounded pressure of water.
B. Their pressure made inside bodies is less than that surrounded pressure of water
C. The density of dead body is equal to that of water.
D. Volume of body displaced is equal to volume of water.
E. Pressure of dead body is equal to that of atmospheric pressure.
iv. Aluminum is used in making motor engines pistons and cylinders due to its:
A. Low density and high thermal conductivity.
B. Low density and low thermal conductivity.
C. It's good conductor of heat than copper.
D. Thermal expansivity is high.
E. It's stronger enough to maintain high temperature.
v. One of the assumptions made when demonstrating how to determine specific heat
capacity of substance by the mixture method is that:
A. No heat lost to the surrounding, heat absorption by apparatus.
B. Heat lost to the surrounding, heat absorption by apparatus.
C. No heat lost to the surrounding, heat absorption by apparatus.
D. Heat lost to the surrounding, no heat absorption by the apparatus.
E. Calorimeter is apparatus for demonstrating.
vi. The phenomenon of melting under pressure and re-freezing when pressure reduced is
called:
A. Ebullition B. Triple point of water
B. Regelation D. Depression
C. Equilibrium
vii. Sweeting uses the cooling effects caused by:
A. Osmosis B. Diffusion
B. Freezing D. Evaporation
C. Saturated water
Page 2 of 6
viii.
ix.
x.
A lens camera of focal length 15cm is used to take a picture of a man of height 1.8M,
if a man is standing 10M ahead of the camera, what is magnification of the image:
A. 1.8
B. 1.5
C. 0.00152
D. 0.00142
E. 0.005
Mercury from Spheroid drops when split on a wooden bench because:
A. Its velocity is very high.
B. It has relative density.
C. It has high cohesive force.
D. It has low surface tension.
E. It is subjected to high atmospheric pressure
A device consists of a coil rotating in an external magnetic field to produce electricity
refers as:
A. Transformer
B. Electric bell
C. Spark coil
D. Generator
E. Galvanometer
2. Match the items of list A with the correct responses from List B so as to produce meaning
full phrase
LIST A
LIST B
(i)
Loudness
A. Sound of regular frequency
(ii) Voiceless
B. Sound of irregular frequency
(iii) Tone
C. Rise and fall of sound waves
(iv) Pitch
D. Intensity of the sound larger amplitude
(v) Thimble
E. More reflection of sound in a closed room
(vi) Reverberation
F. Degree of the highest and lowest tone
G. Quality of sound produced by an instrument
SECTION B (54 Marks)
Answer all questions from this sections
3. (a) A micrometer screw gauge has a
error. State the reading that is observed
on the instrument when used to measure the diameter of the wire whose actual diameter
is 0.38mm
(b) Briefly explain any four (04) sources of errors in measurements
Page 3 of 6
4. (a) Figure 1 shows a defective straw used to suck milk from the glass
It was observed that upon sucking the straw, milk did not rise up the straw. Explain this
observation and hence suggest suitable solution for the scenario.
(b) A rectangular block measures 8cm by 5cm by 4cm and has a mass
of1200g. Determine the greatest pressure the block can exert on the floor.
5. (a) Figure 2 shows a round bottomed flask containing a coloured liquid. The flask is
fitted with the capillary tube
It is observed that on holding the flask with bare hands the level of the liquid in the
capillary tube initially drops slightly and then rises. Explain this observation.
Page 4 of 6
(b) An Aluminium solid of mass 26g absorbs 600J of heat when heated. If the initial
temperature of it is 300C. Find its final temperature
6. (a) Why does the sky appear blue during the day as observed from the Earth surface
(b) Which colour will be seen on a white shirt with Green spots when is illuminates
with:i. Red light
ii. Blue light
iii. White light
7. (a) At different time’s scientist have proposed various descriptions of an atom to match
the experimental evidence available. Briefly describe Plum pudding model as proposed
by J.J Thomson.
(b) The element tin has a total of 25 isotopes with the lightest isotope being. Assuming
that all 25 isotopes exist and the difference in mass number of two successive elements is
one. Write down the symbol for heaviest isotope.
8. (a) Figure below shows the graph of Velocity(m/s) against time (sec) for a small steal
ball falling in a viscous fluid
i.
ii.
Describe the motion of the steel ball as represented by part OA
Give reason why the velocity of AB is constant?
(b) A form four student throws a stone of mass 200g vertically upwards from the ground
with the velocity of 80m/s and it lands back after a certain seconds. Determine the total
distance travelled by the stone.
SECTION C (30 Marks)
Page 5 of 6
Answer only two questions from this section
9. (a) State the Hooke’s law
(b)You are provided with five 20g masses, a meter rule, spring with a pointer, a retort
stand and a clamp.
i. Sketch a labelled diagram of the set up that may be used in order to verify Hooke’s
law using these apparatus
ii. State two measurement that should be recorded in order to plot a suitable graph so
as to verify the Hooke’s law
iii. Describe how the measurement in (ii) above can be used to determine the spring
constant
iv. Sketch the nature of the graph for elastic limit is not exceeded.
(c) A helical spring stretches by 0.6cm when supporting a weight of 8.7N. Determine the
extension when the same spring supports the weight of 10.3N
10.(a) Diagram below shows a bottle top opener being used to open a bottle
From the diagram indicate the direction of Load and Effort
(b) State the two ways in which an inclined plane can be made to reduce the applied
effort when pulling a load along the plane
(c) A block and tackle pulleys system of five pulleys and 96.4% efficiency is used to