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Question
Can a hot-wire ammeter be used to measure a direct current of constant value? Do we have to change the graduations?
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Solution
A hot-wire ammeter measures the rms value of current for an alternating current. So, it can be used to measure the direct current of constant value because that constant value will be equal to the rms value of current. As, the rms value of the current is same as the direct current thus we need not change the graduations.
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