Power and efficiency

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Question 15
Easy

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​=31​EA​

EB=EAE_B = E_AEB​=EA​

EB=3EAE_B = 3E_AEB​=3EA​

3EB=EA3E_B = E_A3EB​=EA​

Power and efficiency Questions

  1. GCSE
  2. /Physics
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