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GCSE Standard Questions: Electricity in the Home

Q14. The photo shows a person using an electric lawn mower.

(a) The lawn mower is connected to the mains electricity supply. What is the frequency of the mains electricity supply in the UK?

[2 marks]

(b) The lawn mower has a switch on each side of the handle. Here is the circuit diagram for the lawn mower.

The motor in the lawn mower can only be turned on when the person using it holds the handle of the lawn mower with both hands. Explain why.

[2 marks]

(c) The power input to the motor is 1.8 kW The resistance of the motor is 32 Ω.

Calculate the current in the motor.

[3 marks]

(d) The useful power output from the motor is 1.5 kW

Calculate the time it takes for the motor to transfer 450,000 J of useful energy.

[3 marks]

(Total 11 marks)