Room A and Room B are identical rooms. No energy can escape from the rooms. The temperature of each room is increased by using a different heater. Room A has a heater with power rating 1.5 kW. Room B has a heater with power rating 4.5 kW.
The heater in each is turned on for 45 minutes45\text{ minutes}45 minutes. Let EA E_A\,EA be the increase in the thermal energy store of Room A, and EB E_B\,EB be the increase in the thermal energy store of Room B.
Which of the following relationships is correct?
EB=13EAE_B = \frac{1}{3}E_AEB=31EA
EB=EAE_B = E_AEB=EA
EB=3EAE_B = 3E_AEB=3EA
3EB=EA3E_B = E_A3EB=EA
37 exam-style questions on OCR GCSE Physics Power and efficiency. Each one has a worked solution and a mark scheme showing where the marks go.