Question

7, Which of the two, a magnetic compass or LED, is better to use in a tester and why?
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Answer 1

Answer:

When a weak current is passed through a circuit with an electric bulb, the bulb does not glow as the current is not sufficient enough to do so. But, when the electric bulb is replaced by a LED bulb, it glows because an LED bulb requires only a small amount of current to glow. In the similar way, when a magnetic compass is connected in the same circuit, the needle shows slight deflection which indicates the presence of current. More the current, more the deflection. The needle comes to zero only when the current is zero.

Hence, a LED bulb or a magnetic compass indicates the presence of a weak current in the circuit.

Explanation:

Hope you understand it. Have a good day