Pearson Edexcel International GCSE (9–1) · PHYSICS · Chapter
Energy Transfers
18 practice questions
Practice questions
1–10 of 10 · Normal
Question 1
1 mark · Normal
Answer and check →Which method of thermal energy transfer does NOT require particles or matter to move at all?
- A.Conduction
- B.Convection
- C.Radiation
- D.Evaporation
Question 2
3 marks · Normal
Answer and see the solution →On a clear night, the temperature inside houses often drops even when windows and doors are closed and no air escapes.
(a)[3 marks]Explain, using ideas of energy transfers, why the inside of the house cools down during a clear night.
Question 3
3 marks · Normal
Answer and see the solution →Explain why a house with thick loft insulation and double glazing loses less heat in winter, referring to conduction, convection and radiation.
(a)[3 marks]Explain how each method of heat transfer is reduced by these features.
Question 4
4 marks · Normal
Answer and see the solution →A cyclist uses an electric light powered by a small dynamo attached to the bicycle wheel. When cycling, the dynamo transfers energy from the movement of the wheel to other forms.
(a)[1 mark]Name the main useful energy output from the dynamo.
(b)[1 mark]State one form of energy that is wasted during the operation of the dynamo.
(c)[2 marks]Describe, using the idea of energy stores, how energy is transferred from the cyclist’s body to the moving bicycle and eventually produces light.
Question 5
3 marks · Normal
Answer and see the solution →A laptop charger takes in 120 kJ of electrical energy from the mains and transfers 21 kJ of that to heat, which is not useful. Calculate the efficiency of the charger, giving your answer as a percentage.
Question 6
3 marks · Normal
Answer and see the solution →A student investigates how the colour of a can affects how much heat it radiates. She heats two cans, one painted matt black and one painted shiny white, to the same temperature and then measures their temperatures as they cool.
Their results are shown in the table:
Cooling of cans with different surface colours Time (min) Matt black can (°C) Shiny white can (°C) 0 80 80 2 72 75 4 65 71 6 59 68 8 54 66 (a)[2 marks]Plot a line graph of the temperature of each can against time. Draw both lines on the same axes. Label your axes.
(b)[1 mark]State which can radiates heat faster and explain why, using the graph.
Question 7
3 marks · Normal
Answer and see the solution →Explain how convection causes a breeze to blow from the sea towards the land during a sunny day at the beach. Include reference to temperature differences and movement of air.
Question 8
4 marks · Normal
Answer and see the solution →The diagram shows a cross-section of an external house wall constructed with two layers of brick and a cavity filled with insulation material.
(a)[2 marks]Explain why the walls of modern houses are made with a cavity containing insulation material rather than being solid brick.
(b)[2 marks]Name two ways that the cavity and the insulation reduce energy transfers from inside the house to outside, stating the method of energy transfer each affects.
Question 9
4 marks · Normal
Answer and see the solution →Describe an experiment to compare how quickly heat travels by conduction along rods made of copper and steel. Your answer should include apparatus, the method, the measurement you would take, and how you would know which material conducts heat better.
Question 10
1 mark · Normal
Answer and check →Which of the following is not a way to improve the energy efficiency of a house?
- A.Adding insulation to roof spaces
- B.Installing double-glazed windows
- C.Painting radiators with matt black paint
- D.Sealing gaps around doors and windows