Question

Mention the condition under which charges can move in a conductor name the device which is used to maintain this condition in an electric circuit name the device that measures it

Answer 1

voltmeter,ammeter.....

Answer 2

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Charge can move in a conductor only when a potential difference is maintained between it's ends .

A cell or a battery is used to maintain potential difference and hence , there is a flow of electric charges in an electric circuit .

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