(a(i))[2]
State two ways in which useful energy is transferred from the television.
(a(ii))[1]
Find the amount of wasted energy output from the television.
(b(i))[3]
Describe how a hydroelectric power station generates electrical power.
(b(ii))[2]
Apart from cost, state one advantage and one disadvantage of generating electrical power using a hydroelectric power station compared to a coal-fired power station.