Questions 1
(a) Topic – 9.c
(b) Topic-9.c
The Hertzsprung-Russell (HR) diagram shown can be used to classify stars.
(a) Three regions in the HR diagram are labelled P, Q and R. The boxes show the three regions and different astronomical objects. Draw a straight line from each region to the type of astronomical object contained in that region.
(b) Define the term absolute magnitude.
▶️Answer/Explanation
Ans
(a) one mark for each correct line;
(b) (a measure of) brightness;
(of a star) at a {standard / fixed / same / set} distance;
Questions 2
(a) Topic – 1.c
(b) Topic-1.c
(c) Topic-3.c
A wrench is used to turn a nut.
(a) The force applied to the wrench is 28N. Calculate the moment applied by the wrench on the nut. Give a suitable unit.
(b) State two changes that could be made to increase the size of the moment applied to the nut.
(c) Diagram 2 shows the wrench as it is turned through 90°.
(i) The force is applied over a distance that is equal to a quarter of the circumference of a circle. The circle has a radius of 15cm. Calculate the distance over which the force is applied.
[circumference of circle = 2×π×radius]
(ii) Calculate the work done by the force as the wrench is turned through a quarter of the circumference of the circle.
▶️Answer/Explanation
Ans
(a) substitution into moment = force × distance;
evaluation;
matching unit;
e.g.
moment = 28 × 0.15
(moment =) 4.2 N m
(b) apply a larger force / eq;
apply force further from nut / eq;
(c) (i) circumference of circle calculated;
divided by 4 to find distance;
e.g.
(circumference = 2πr = 2 × π × 15) = 94(.2) (cm)
(distance = 94 / 4 =) 24 (cm)
(ii) conversion of cm to m;
substitution;
evaluation;
e.g.
work done = force × distance
work done = 28 × 0.24
(work done =) 6.7 (J)
Questions 3
(a) Topic – 5.c
(b) Topic-5.c
A student investigates how much infrared radiation is absorbed by different surfaces.
(a) The photograph shows some of the equipment available to the student.
The student pours some water into each bottle. Describe a method the student could use to investigate how the colour of the bottle affects the amount of infrared radiation absorbed by the bottle. You may draw a diagram to help your answer.
(b) The student plots a graph to show how the temperature of the water in each bottle varies with time. Draw two curves to show the expected variation in temperature of the black bottle and the silver bottle during the investigation. Label your curves with the colour of each bottle.
▶️Answer/Explanation
Ans
(a) any six from:
MP1. idea of equal volume of water in each bottle;
MP2. place both bottles an equal distance from the heater;
MP3. idea of same heater output for both bottles;
MP4. same starting temperature of water in both bottles;
MP5. measure temperature of water in both bottles after a given time;
MP6. repeat investigation (more than once);
MP7. calculate a mean;
MP8. safety guidance to avoid the hazard of burn/scald/electrocution;
(b) two lines drawn showing an increase in temperature over time;
line identified by candidate as black is always above the line identified by candidate as silver;
Questions 4
(a) Topic – 2.d
(b) Topic-2.d
This question is about electrostatics.
(a) A polythene rod is rubbed with a cloth, which causes both the rod and the cloth to become charged.
(i) Which of these is the force that causes the rod and the cloth to become charged?
A friction
B gravitational
C magnetic
D tension
(ii) The polythene rod becomes negatively charged. Which of these statements explains how the rod has become negatively charged?
A the rod gains electrons
B the rod loses electrons
C the rod gains protons
D the rod loses protons
(b) A student has rods made from different materials. The student rubs each rod the same way with a cloth. The student measures the charge gained by each rod three times. The table shows the results.
(i) One of the readings for the polythene rod is anomalous. Circle the anomalous result in the results table.
(ii) State how the student should deal with the anomalous result.
(iii) Calculate the mean charge for the polythene rod.
(iv) Describe how the student could use the rods to demonstrate that there are two different types of electric charge.
▶️Answer/Explanation
Ans
(a) (i) A (friction);
B is incorrect because gravity is not the force
C is incorrect because magnetic is not the force
D is incorrect because tension is not the force
(ii) A (the rod gains electrons);
B is incorrect because this would produce a positive charge
C is incorrect because protons are not transferred
D is incorrect because protons are not transferred
(b) (i) reading at −80 circled
(ii) repeat or check that test or that result / ignore the result /
idea of not including (that result) in the mean;
(iii) mean calculated including anomaly giving an answer that rounds to -67 = 1 mark max;
mean calculated correctly ignoring anomaly i.e. -60 = 2 marks;;
(iv) MP1 : suitable apparatus that would demonstrate rod is charged
MP2: indication that a charged rod will apply a force on the ‘other object’
MP3: evidence that both attraction and repulsive forces will happen with opposite and like charges
Questions 5
(a) Topic – 5.c
(b) Topic-5.b
(c) Topic-5.c
This question is about sound.
(a) State which wave property determines the pitch of a sound.
(b) The bar chart shows the maximum frequency of sound heard by four animals and a human.
Explain which of the bars is most likely to show the results for a human.
(c) A sound wave has a frequency of 500Hz.
(i) Show that the time period of the sound wave is 2.0ms.
(ii) The diagram shows the screen of an oscilloscope. The timebase of the oscilloscope is 0.50ms per square.
Draw the trace on the oscilloscope screen when the sound wave is detected.
▶️Answer/Explanation
Ans
(a) frequency;
(b) C chosen;
(because) humans can hear up to 20 kHz / 20 000Hz;
(c) (i) substitution into f = 1/T;
rearrangement;
evaluation in seconds and appropriate conversion to ms;
e.g.
500 = 1/T
T = 1/500
T = 0.002 s = 2(.0) (ms)
(ii) one or more complete wave(s) drawn with consistent period by eye;
each cycle is 4 squares;
Questions 6
(a) Topic – 7.c
(b) Topic-7.c
This question is about electromagnets.
(a) Describe the construction of a simple electromagnet that is producing a magnetic field. You may draw a diagram to help your answer.
(b) A proton moves through a uniform magnetic field produced by a strong electromagnet. The shaded area in the diagram represents the magnetic field. The initial velocity, v, of the proton is also shown.
(i) Use the left-hand rule to determine the direction of the force acting on the proton.
(ii) Explain how the force on the proton changes as the proton moves through the magnetic field. You may add to the diagram to help your answer.
(iii) Suggest why the velocity of the proton changes.
▶️Answer/Explanation
Ans
(a) solenoid / coil (of wire);
(direct/d.c.)current in the wire/coil/solenoid;
(soft) iron core;
(b) (i) idea of upwards/ towards top of page;
any TWO from:
force (always) at right angles (to velocity);
causes the proton’s direction to change;
(because) proton motion is equivalent to a current;
(this causes) the direction of the force on the proton to change;
idea of magnitude of force is constant;
(iii) (velocity changes because) the direction changes;
Questions 7
(a) Topic – 3.d
(b) Topic-3.d
(c) Topic-3.d
A hydroelectric power (HEP) station generates electricity from renewable energy resources.
(a) State what is meant by the term renewable energy resource.
(b) The diagram shows the design of a HEP station.
Water flows from the upper lake to the lower lake through the turbine. The turbine is connected to a generator, which generates electricity. Describe the energy transfers involved in generating electricity in the HEP station.
(c) The HEP station is located near a large wind farm.
(i) Give one advantage of generating electricity using the HEP station rather than the wind farm.
(ii) Give one disadvantage of generating electricity using the HEP station rather than the wind farm.
(iii) The HEP station has an electric pump that can pump water from the lower lake back to the upper lake. The pump can be powered using electricity generated by the wind farm.
Explain how the HEP station and wind farm can be used together to maximise the effectiveness of generating electricity.
▶️Answer/Explanation
Ans
(a) idea that source will not run out / can be replaced;
(b) any four from:
MP1. water has (high) {gravitational potential energy/GPE (store)} ;
MP2. water loses GPE / gains {kinetic energy/KE};
MP3. transfers mechanically (to water or to turbine or to generator);
MP4. energy is transferred electrically (from power station);
MP5. energy is wasted by heating/radiation e.g. IR, sound;
(c) (i) any one from:
● idea that energy can be supplied more reliably by HEP;
● idea that HEP produces less (environmental) noise;
● idea that HEP can respond (quickly) to demand;
(ii) any one from:
● large area of land needs to be flooded;
● location dependent / mountainous area;
● damage to habitats / eq;
(iii) any THREE from:
MP1 idea that wind farm cannot store energy;
MP2 idea of wind powering the pump when (energy) demand is low;
MP3 idea that (therefore) upper lake acts as an energy store (for wind farm output);
MP4 (so that) energy released from upper lake or to the HEP when demand is high
MP5 idea that more electricity/energy is transferred usefully;
Questions 8
(a) Topic – 4.c
(b) Topic-4.c
(c) Topic-4.c
The photograph shows a water bath that a technician uses to heat some water.
(a) The water bath is filled with water at an initial temperature of 15°C. Calculate the initial temperature of the water in kelvin.
(b) The technician heats the water to a final temperature of 60°C.
(i) Describe how the energy of the water molecules changes as the temperature of the water increases.
(ii) The table shows some information about the heating element in the water bath and the heating process.
Calculate the energy transferred by the heating element in the water bath during the heating process.
(iii) Calculate the mass of water being heated. Assume that all the energy is transferred to the thermal store of the water.
[for water, specific heat capacity = 4200J/ kg°C]
(c) Some water evaporates as a gas from the water bath.
(i) Describe the arrangement of particles in a gas.
(ii) Describe two differences between evaporation and boiling.
▶️Answer/Explanation
Ans
(a) 288 (K);
(b) (i) (energy of molecules) increases;
kinetic energy increases;
(ii) substitution into E = V × I × t;
conversion of minutes to seconds;
evaluation;
e.g.
time = 45 × 60 = 2700 (s)
energy = 230 × 1.5 × 2700
energy = \(9.3 × 10^5 (J)\)
(iii) substitution into Q = m × c × ∆T;
rearrangement;
evaluation;
e.g.
\(9.3 × 10^5\) = mass × 4200 × (60-15)
mass = \(9.3 × 10^5 / 4200 × 45\)
(mass =) 4.9 (kg)
(c) (i) particles are arranged randomly;
idea that particles are spread out or are widely spaced;
(ii) boiling happens at a specific or fixed temperature or 100°C, but evaporation happens at any temperature;
boiling happens throughout a liquid but evaporation only happens at the surface /eq ;