EM, EMI

Question 1

Magnetic Field

Answer 1

A magnetic field is a region of space where a permanent magnet or a moving charge or a current-carrying conductor will experience a magnetic force.

Question 2

Magnetic Flux Density

Answer 2

The magnetic flux density of a magnetic field is defined as the force per unit current per unit length acting on a straight current-carrying conductor placed at right angles to the magnetic field.

Question 3

Magnetic flux

Answer 3

Magnetic flux through a plane
surface is the product of the flux density normal to the surface and the area of the surface.

Question 4

Magnetic flux linkage

Answer 4

Magnetic flux linkage through a coil of N turns is the product of the number of turns N of the coil and the magnetic flux linking each turn.

Question 5

Faraday’s Law of Electromagnetic Induction

Answer 5

Faraday’s Law of Electromagnetic Induction states that the induced e.m.f. is directly proportional to the rate of change of magnetic flux
linkage.

Question 6

Lenz’s law

Answer 6

Lenz’s law states that the direction of the induced e.m.f. is such as to cause effects to oppose the change producing it.