Question

The reason a moving coil galvanometer cannot be used with an alternating current is that

• A. The coil bends easily
• B. The coil heats up too much
• C. Sparks can be produced
• D. The net magnetic field produced is zero

Answer 1

The correct option is D The net magnetic field produced is zero

Since direction of magnetic field depends on the direction of current. So, the direction of magnetic field reverses as soon as direction of current gets reversed. In alternating current, current reverses its direction at a constant period and so the magnetic field. Thus net magnetic field produced in the galvanometer will be zero with alternating current and there will be no deflection in the galvanometer.