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Figure one shows a circuit diagram for controlling the temperature of a room.

(i) State and explain the purpose of the bimetallic strip.
(ii) Describe how the circuit controls the temperature when the switch S is closed.

Answer Text:
i)- To make and break the contact or circuit. It bends when the temperature increases and straightens when the temperature reduces.
ii)- When the switch is closed, the current flows, heating takes place and the temperature of the strip rises making it to bend away from contact disconnecting the heater. The temperature drops and the strip straightens
completing the circuit again.