# Induced current, induced emf and electromagnetic induction. How is induced emd product and on which factors it depends.

Electromagnetic Induction

Induced Current

The current produces in the conductor due to (as a result of) its motion in the magnetic field is called induced current.

Induced emf

The emf produces in the conductor as a result of (due to) its motion in the magnetic field is called induced emf.

Induced emf = (Induced current) × (Resistance of conductor)

Induced emf = I × R

Electromagnetic Induction

The process/mechanism in which current produces (generates) in the conductor due to its motion in the magnetic field is called electromagnetic induction.

Explanation

Consider a straight wire of length L placed in the magnetic field. The wire is connected (joined) to a sensitive galvanometer. This forms a closed path or loop without any battery (a battery is an electrical device having positive and negative pools). In the beginning, when the loop is at rest, no current is shown by the galvanometer.

If the loop is moved from left to right, current flows into the loop in the anti-clockwise direction. If we stop the motion of the loop, the current also stops. If the loop is moved in the opposite direction, (right to left) current also reverses its direction (clockwise). This is indicated by the deflection of the galvanometer in the opposite direction. The induced current increases by using

(i) stronger magnetic field.
(ii) Faster motion of the loop.
(iii) Increasing on of turns of the coil.

The product of induced current (I) and resistance of the conductor (R) is called induced emf.

I × R = Induced emf

The relative motion of the loop and magnet causes to produce the induced emf. The relative motion changes the magnetic flux of the loop. The greater (higher) the rate of change (alternation) of flux, the large will be induced emf.