Question

Alternating current cannot be measured by D.C. ammeter because ____________.

Options

• A.C. cannot pass through D.C. ammeter

• average value of complete cycle is zero

• A.C. is virtual

• A.C. changes its direction

Answer 1

Alternating current cannot be measured by D.C. ammeter because average value of complete cycle is zero.

Explanation:

A coil is free to revolve in the magnetic field of a stationary magnet in a D.C. ammeter. When an alternating current is supplied through such a coil, the torque reverses direction every time the current changes direction, and the torque averages zero.