Marking Scheme Paper 3
Question Answer Mark
1 (a)(i) Manipulated variable = Depth of the rod immersed // d 1
(ii)
Responding variable = Reading of spring balance // Bouyant Force // F 1
(iii)
Constant variable = Cross sectional area of rod // Density of liquid // Gravitational Force, g
1
(b) (i) W0 = 9.3 N 1
(ii) W = 8.5, 7.7, 7.0, 6.3, 5.6 All correct : 2 marks At least 3 correct : 1 mark
2
(iii) F = 0.8, 1.6, 2.3, 3.0, 3.7 1
(c)
d/cm W/N F/N
5.0 8.5 0.8
10.0 7.7 1.6
15.0 7.0 2.3
20.0 6.3 3.0
25.0 5.6 3.7
1 mark – 3 columns for d, W and F
(d) Draw the graph of x against W .
A - Label y-axis and x-axis correctly √ B - States the unit at the axis correctly √
Show the horizontal line to the y-axis, x = 1.0 m
Show the vertical line to the x-axis, 1f = 1.6 x 10-3 Hz-1 1
Draw a sufficient large triangle (8 cm x 10 cm)
Substitute correctly ( according to the candidate’s graph) 4.5−0
7.2×10−3−0
State the correct value of the gradient with unit m = 625 m Hz (with correct unit)
(c) decreases 1 1
(d)
State one correct precaution
The position of the eye must be perpendicular to the scale reading// Repeat the experiment to get the average value//
Do experiment at open space
1 1
3 (a) State a suitable inference
The rise in temperature depends on the heat absorbed
1 1
(b) State a relevant hypothesis The higher the heat absorbed, the higher the rise in temperature 1 1 (c)(i)
State the aim of experiment
To investigate the relationship between the heat absorbed and the rise in temperature
1 1
(ii)
State the manipulated variable and the responding variable Manipulated : heat absorbed
Responding : rise in temperature
1 1
State ONE variable that kept constant Volume/density of water/time of heating
1 1
(iii) Complete list of apparatus and materialsThermometer, immersion heater, water, power supply, beaker 1 1
(iv)
Arrangement of apparatus : 1 1
(v)
State the method of controlling the manipulated variable 1. The set-up of the apparatus is as shown in figure above.
2. The immersion heater with power, P of 20 W is used to heat up the water for 3 minutes.
State the method of measuring the responding variable
3. The temperature, T is measured using thermometer. The rise of temperature is calculated using formula
∆ = final temperature – initial temperature and recorded.Ɵ Repeat the experiment at least 4 times
4. The experiment is repeated by using P = 40, 60, 800 and 100 W
1
1
1
3
(vi) Tabulation of data:
Power /W // Heat/J T//∆ / Ɵ oC
1 1
Thermometer
(vii)
Analyze the data. T//∆ / Ɵ oC
Heat,Q/J
1 1
Total marks 12 12
4
(a) State a suitable inference
Current induced/produced depends on the number of turns of coil 1 1
(b) State a relevant hypothesis
The greater the number of turns of coil, the greater the current induced 1 1
(c) (i) State the aim of experiment
To investigate the relationship between the number of turns of coil and current induced
1 1
(ii) State the manipulated variable and the responding variable Manipulated variable: the number of turns of coil on solenoid, n Responding variable : magnitude of current induced, I
State ONE variable that kept constant
Fixed variable : strength of bar magnet // height of magnet, h // Resistance/diameter of wire
.
1 1
1
3
(iii) Complete list of apparatus and materials
Ammeter/microammeter/galvanometer, retort stand, copper wire, connecting wire
1 1
(v) State the method of controlling the manipulated variable 1. The set-up of the apparatus is as shown in figure above.
2. Start the experiment with n=50 turns of coil on solenoid. Drop the bar magnet into the solenoid at constant height of h=50 cm.
State the method of measuring the responding variable
3. Record the magnitude of induced current produced by galvanometer.
Repeat the experiment at least 4 times
4. Repeat the experiment by using n = 60, 70, 80 and 90.
1
1
1 3
(vi)
1 1
Number of turns of coil, n Current, I
(viii)
1 1
TOTAL 12 12
Current, I
