Electro Magnetic Induction And Alternating Currents Question 79
Question: Alternating current can not be measured by dc ammeter because [AIEEE 2004]
Options:
A) ac cannot pass through dc ammeter
B) Average value of complete cycle is zero
C) ac is virtual
D) ac changes its direction
Show Answer
Answer:
Correct Answer: B
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.
