Question
Question: Alternating current can not be measured by dc ammeter because...
Alternating current can not be measured by dc ammeter because
A
ac cannot pass through dc ammeter
B
Average value of complete cycle is zero
C
ac is virtual
D
ac changes its direction
Answer
Average value of complete cycle is zero
Explanation
Solution
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.