Safety devices

2 marks · Normal

An electrical appliance has double insulation and does not have an earth wire. Explain why it is safe to use without an earth wire.

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The double insulation ensures that no live part can be touched, so there is no risk of electric shock, making the earth wire unnecessary.

Also accept: No exposed metal parts; Insulation prevents contact with live wires

Common mistakes: Suggesting earth wire is still needed for all appliances

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Marking points

B1 · 1 mark · Explains double insulation prevents user touching live components

B2 · 1 mark · States earth wire is not required as a result

Worked solution

Double insulation means there are two layers of insulating material, so no live part can be touched. Therefore, an earth wire is not needed.