Nov 2020 / Paper 52
1
Diagram
Copy diagram plus add:
P attached to string
string passing over a supported
pulley
string
horizontally
attached
to
trolley
2
3
labels for pulley and P
Defining the
m is the independent variable and v is the dependent variable
problem
vary m and measure v
keep P constant
Methods of
First of all, measure the mass m using an electronic balance.
data
Then measure the distance d using a rule or a measuring tape.
collection
Then set up apparatus as shown in the diagram.
Now measure v. Release the trolley from rest and determine t, the time taken by the trolley to
travel the distance d, from the electronic timer (or using a stopwatch / or record motion of trolley
using a video camera with timer on and then playback in slow motion mode to get time t). The
speed v of the trolley at distance d is given by v = 2d /t. {How???????????????? Average speed
= (u + v)/2 = TD/TT (0 + v ) / 2 = d / t v = 2d / t}. Hence calculate 1/v2.
4
Repeat experiment for different m.
Method of
plot a graph of 1 / v2 against m
analysis
If graph is a straight line not passing through the origin then the eqn is valid.
5
6
;
Safety
Place cushion or sand box under falling mass to prevent injury
consideration
Place 2 barriers, one on either side of the trolley to prevent it from falling off the bench.
Additional
Use same mass attached to end of string to ensure m is constant.
details
For each m repeat experiment to find average t or v
Another variable to keep constant is d – do not change positions of LGs.
Use a large distance for d so that % uncertainty in t and therefore v is small.
Another method to keep d constant: mark starting and end positions
ensure wooden surface is horizontal, e.g. use spirit level
Ensure string is horizontal – use long string + spirit level.
Use clamp to hold trolley and release it consistently.
Attach string to trolley and mass P by means of strong tape or glue.
1
June 2020 / Paper 52
1
Diagram
2
Defining the
A is the independent variable and f is the dependent variable
problem
vary A and then measure f
keep M constant
First of all, determine A. Use a micrometer to measure diameter of cord in 2 perpendicular
3
Methods of
directions. Find average d. Calculate area using A = d2/4. Hence calculate 1/A
data
collection
Set up apparatus as shown in diagram.
Set frequency of S.G to very low value. Increase frequency slowly until wave pattern is
observed. Read f directly from S.G. Hence calculate f2.
4
Repeat experiment for different A using cords of different diameters.
Method of
Plot a graph of f2 against 1/A.
analysis
If graph is a straight line through the origin, then eqn is valid.
5
Safety
consideration
6
use safety goggles/safety screen to prevent injury to eyes from (moving) elastic cord/load or
in case wire snaps
use cushion/sand box in case load falls if wire snaps
Additional
Use same load throughout experiment to ensure M is constant.
details
For each A, repeat experiment and find average f.
Another variable to keep constant L – do not move stand and fixed support during experiment
Measure mass of the load on top-pan balance
Measure L using rule or tape.
Use cords of the same material/density
Use CRO to determine f (or T) + method to determine T from CRO, e.g. period = time base
× length of one wave ; f = 1 / T {OR f CAN BE READ DIRECTLY FROM S.G}
detail on determining frequency at the maximum amplitude, e.g. increase frequency until the
amplitude starts to decrease, then decrease frequency
2
March 2020 / Paper 52
1 Diagram
Copy figure 1.2 plus add:
Upper part of spring supported by stand + clamp
Coil of wire connected to ac voltmeter or
multimeter or CRO
Rule clamped close to magnet
Show 2 magnets – in equilibrium position and
displaced position and label displacement of
magnet as x.
2 Defining the
x is the independent variable and E is the dependent variable,
problem
vary x and then measure E.
variable to be kept constant is m.
Set up apparatus as shown in diagram.
First of all, measure x. Use a vertically clamped meter rule positioned as close as possible to the magnet. Use set square
3 Methods of
data collection
to determine equilibrium position a (initial height of centre of magnet above bench) and displaced position b (final height
of centre of magnet above bench). x = difference between a and b.
Then determine E. Value of E will vary. Record voltmeter reading or trace on CRO using video camera. Playback frame
by frame/slow motion mode to determine maximum emf E.
4 Method of
analysis
5 Safety
Repeat experiment for different x.
Plot graph of E against x.
If graph is a straight line passing through the origin then equation is correct.
Comparing eqn with y = mx + c, gradient = ……
Use safety goggles / safety screen to prevent injury (to eyes) from (detached) spring/magnet; use cushion / sand box
in case magnet falls
consideration
use g- clamp / weights on stand to prevent toppling.
6 Additional
Use same magnet throughout experiment to ensure m is constant.
details
For each x, repeat E and then average.
Other variables to be kept constant:
use same magnet + measure/check B using Hall probe ;
1.
B
2.
N Use same coil
3.
k
Use same spring
Measure m using electronic balance.
Keep distance between equilibrium position and coil constant.
Do not stretch spring beyond elastic limit - Check that the unstretched length of the spring has not changed or spring is
not permanently deformed (after removing magnet).
Expression to determine k from separate experiment, e.g. k = mg /extension
Measure B using a (calibrated) Hall probe + detail on use of Hall probe, e.g. adjust probe until maximum value or
measure B using Hall probe first in one direction and then in the opposite direction and average.
Method to maximise E, e.g. Position magnet so that equilibrium position is at the centre of the coil or use a large number
of turns.
Method to ensure clamped rule to measure x is vertical, e.g. correctly positioned set square
at right angles between the rule and the horizontal surface/bench or use spirit level
3
