Electromagnetism and EMI

Question 1

Magnetic flux density, B

Answer 1

The force per unit current per unit length acting on an infinitely long current carrying conductor placed perpendicularly to the magnetic field. Unit: tesla (T)

Question 2

Tesla

Answer 2

The magnetic flux density of a magnetic field is one tesla if the force acting on 1m length of a conductor carrying 1A of current placed perpendicular to the magnetic field is 1N.

Question 3

Magnetic flux

Answer 3

Magnetic flux through a plane is the product of the magnetic flus density normal to the surface and the area of the surface.
Unit: Wb

Question 4

1 Weber

Answer 4

The magnetic flu ex through a surface of 1m^3 if there is magnetic flux density of 1T perpendicular to the areas

Question 5

Magnetic flux linkage

Answer 5

The product of the number of turns of the coil and the magnetic flux linking each turn.

Question 6

Faraday’s law

Answer 6

The magnitude of the induced emf is directly proportional to the rate of change of magnetic flux linkage.

Question 7

Lenz’s law

Answer 7

The polarity of the induced emf is such that it tends to produce a current that creates a magnetic field so as to oppose the change in magnetic flux.

Question 8

Electronvolt (eV)

Answer 8

The energy gained by an electron when it is accelerated through a potential difference of one volt