**Paper 1 H - SAMPLE SET 1 Q13**

13) An electrician is replacing an old electric shower with a new one.

The inside of the old shower is shown in

The inside of the old shower is shown in

**Figure 19**.13.1) If the electrician touches the live wire he will receive an electric shock.

Explain why. [4 marks]

Different electrical wires need to have a cross-sectional area that is suitable for the power output.

Explain why. [4 marks]

Different electrical wires need to have a cross-sectional area that is suitable for the power output.

**Figure 20**shows the recommended maximum power input to wires of different cross-sectional areas.13.2) The new electric shower has a power input of 13.8 kW.

Determine the minimum

The diameter, d, can be calculated using the equation:

Determine the minimum

**diameter**of wire that should be used for the new shower.The diameter, d, can be calculated using the equation:

A is the cross-sectional area of the wire. [2 marks]

Minimum diameter = _________ mm

13.3) The charge that flows through the new shower in 300 seconds is 18 000 C. The new electric shower has a power of 13.8 kW.

Calculate the resistance of the heating element in the new shower.

Write down any equations you use. [5 marks]

Calculate the resistance of the heating element in the new shower.

Write down any equations you use. [5 marks]

Resistance = __________ Ω

**(Total for Question 13 = 11 marks)**