Electromagnetic Induction

Question 1

Define magnetic flux and its formula.

Answer 1

The magnetic flux through a plane surface is the product of the component of the magnetic flux density to the surface and the area of the surface.

Φ = ABcosθ

Question 2

Define magnetic flux linkage and its formula.

Answer 2

The magnetic flux linkage is defined as the product of the number of turns of the coil and the
magnetic flux through each turn.

linkage = NΦ

Question 3

State Faraday’s Law of Electromagnetic Induction and its formula.

Answer 3

The magnitude of the induced e.m.f is directly proportional to the rate of change of magnetic
flux linkage or rate of cutting of magnetic flux.

ε = dΦ/dt = B(dA/dt) = BLv

Question 4

State Lenz’s Law.

Answer 4

It states that the polarity of the induced e.m.f is such that it tends to produce a current that
creates a magnetic field so as to oppose the change in magnetic flux.