Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Energy Resources and Energy Transfers
175 practice questions
Topics covered
Practice questions
171–175 of 175
Question 171
6 marks · Normal
Answer and see the solution →The diagram shows a rectangular solar heating panel used to heat water for a home. Water enters the pipe at A and leaves at B after flowing through the panel. The inside of the panel is painted matt black and covered by a glass sheet.
Solar heating panel (not to scale) (a)[2 marks]Explain why the inside surface of the panel is painted matt black.
(b)[1 mark]Suggest one reason for covering the panel with a glass sheet.
(c)[2 marks]State and explain which energy transfer process is mainly responsible for transferring energy from the Sun to the panel.
(d)[1 mark]Describe how convection helps heat water inside the pipe.
Question 172
6 marks · Normal
Answer and see the solution →In a hydroelectric power station, water of mass 2.0 × 10^5 kg falls from a height of 50 m every minute to turn the turbines. The electrical power output of the station is 1.0 MW (1.0 × 10^6 W). Assume g = 10 N/kg.
(a)[2 marks]Calculate the total gravitational potential energy lost by the water each minute.
(b)[2 marks]How much electrical energy is produced by the station each minute?
(c)[2 marks]Calculate the efficiency of the power station.
Question 173
5 marks · Normal
Answer and see the solution →A metal saucepan is placed on a stove to heat water for cooking. The saucepan has a metal handle, but some are designed with a wooden covering on the handle.
(a)[2 marks]State and explain which process is mainly responsible for transferring thermal energy from the flame to the water.
(b)[2 marks]Explain why it is beneficial for the handle to have a wooden covering, using ideas about thermal conductivity.
(c)[1 mark]Give the correct SI unit for energy.
Question 174
6 marks · Normal
Answer and see the solution →A student of mass 45 kg runs up a staircase that is 3 meters high in 8 seconds.
(a)[2 marks]Calculate the change in gravitational potential energy (GPE) of the student.
(b)[3 marks]Calculate the average power generated by the student while running up the stairs.
(c)[1 mark]State the correct unit for power.
Question 175
5 marks · Normal
Answer and see the solution →A power station uses natural gas to generate electricity. Some of the energy from burning gas is used for useful work; some is wasted as heat.
(a)[1 mark]State the unit of power and give its symbol.
(b)[2 marks]The power station transfers 2.4 × 10^8 J of useful electrical energy every second. Calculate its useful power output. Give your answer in MW.
(c)[2 marks]Explain why the total energy output of the power station is more than just the useful energy output.