GCSE Standard Questions: Electricity in the Home

Q8. The photo shows a coffee machine. The coffee machine uses an electric element to heat water.

(a) The coffee machine has a metal case.

Why would it be dangerous for the live wire of the electric cable to touch the metal case?

[1 mark]

(b) The power output of the coffee machine is 2.53 kW.

The mains potential difference is 230 V.

Calculate the current in the coffee machine.

[4 marks]

(c) The coffee machine heats water from 20 °C to 90 °C.

The power output of the coffee machine is 2.53 kW.

Given that the specific heat capacity of water is 4200 J/kg °C, calculate the mass of water that the coffee machine can heat in 14 seconds.

[6 marks]

(Total 11 marks)