Physics-
General
Easy
Question
Alternating current can not be measured by dc ammeter because
- ac cannot pass through dc ammeter
- Average value of complete cycle is zero
- ac is virtual
- ac changes its direction
The correct answer is: Average value of complete cycle is zero
In dc ammeter, a coil is free to rotate in the magnetic field of a fixed magnet.
If an alternating current is passed through such a coil, the torque will reverse it’s direction each time the current changes direction and the average value of the torque will be zero.
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