Question

Why is it important to have a closed circuit in a torch?​

Answer 1

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More current means more electrons are flowing into the filament. Subsequently, more energy is being emitted, or released, in the form of light. When the circuit is closed (that is, when the bottom wire touches the negative terminal of the battery), current can flow through the circuit.

Answer 2

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More current means more electrons are flowing into the filament. Subsequently, more energy is being emitted, or released, in the form of light. When the circuit is closed (that is, when the bottom wire touches the negative terminal of the battery), current can flow through the circuit.