In a D.C motor the coil in a magnet rotates maximum to about

In a transformer, the primary coil is connected to

A. Alternating current (AC) source

B. Direct current (DC) source

C. resistor

D. inductor

Weak ionic current in our body that travels along the nerve can produce the

A. atoms

B. heat

C. potential difference

D. magnetic effect

Electric motors works on the principle of

A. capacitors

B. friction

C. couple

D. torque

A transformer is designed to convert the voltage from 240 V a.c mains to 12 V, and has 4000 turns on its primary coil. The turns on its secondary coil should be

A. 100

B. 200

C. 120

D. 480

In transformer the changing current in primary coil induces changing magnetic field in

A. resistor

B. inductor

C. insulator

D. secondary coil