Electromagnetic Induction

When a coil rotates in a magnetic field, the induced current in it

• continuously changes direction

• remains same

• becomes zero

• becomes maximum

By increasing the number of turns in a coil, the current in the wire

• decreases

• remains the same

• becomes zero

• increases

The direction of induced current in the coil can be reversed by

• reversing the direction of the battery

• reversing the magnetic field

• keeping the magnet stationery in the coil

• connecting an ammeter in the circuit

An A.C. generator converts kinetic energy to

• electric energy

• potential energy

• light energy

• thermal energy

Metal detectors installed for security purposes are based on the principle of

• potential difference

• electromagnetic difference

• electromagnetic induction

• potential energy