Skip to content

Course home

Sign up

3 Conservation of energy

EasyMediumHard
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114
Question 75
H

An electric kettle is supplied with 360 kJ of energy. The thermal store of the water in the kettle increases by 306 kJ.

a.

Calculate the efficiency of the kettle.

[2]
b.

The body of the kettle is made from a plastic with double walls and a layer of air between them.

Explain how this design increases the efficiency of the kettle.

[2]
c.

A student says:

'In winter, when the kitchen needs heating, this kettle is 100% efficient.'

Discuss whether the student is correct.

[3]
Markscheme

3 Conservation of energy Questions

  1. GCSE
  2. /Physics
  3. /3 Conservation of energy

Question bank