Question

In ac circuit when ac ammeter is connected it reads i current if a student uses dc ammemter in plane of ac ammeter the reading in the dc ammeter will be

Answer 1

the reading will be zero as as the DC ammeter shows average current and the average of an alternating current is zero.

Answer 2

In AC circuit when AC ammeter is connected it reads i current. If a student uses DC ammemter in place of AC ammeter the reading in the DC ammeter will be 0.

The reason is explained below.

1. AC or alternating current, has torque, which changes direction for every half cycle.

2. For this reason, AC measurements are made by moving iron instruments.

3. On the other hand, DC or direct current has a unidirectional torque.

4. DC measurements are thus usually made by Permanent Magnet Moving Coil (PMMC) instruments.

5. Even if we connect DC ammeter to an AC circuit we would get 0 reading.

6. However, this should be avoided as, even if the reading shows 0, the AC current causes the meter to heat up and eventually damage the meter.