Electricity Electromagnetism Definitions

Question 1

A magnetic field is: {Definition}

Answer 1

A magnetic field is: a region where magnetic forces are felt.

Question 2

A magnetic field line is: {Definition}

Answer 2

A magnetic field line is: the path of free north pole would take if it were free to move.

Question 3

Magnetic flux density is: {Formula}

Answer 3

Magnetic flux density is:
B = F/IL
[B = magnetic flux density, F = force, I = Current, L = length] [T]

Question 4

Magnetic flux is: {Formula}

Answer 4

Magnetic flux is:
φ = BA
[φ = Magnetic Flux, B = magnetic flux density, A = area] [Wb]

Question 5

Electromagnetic Induction is: {Definition}

Answer 5

Electromagnetic Induction is: An EMF is induced in a conductor when there is a changing magnetic flux cutting the conductor.

Question 6

Faraday’s Law states: {Definition}

Answer 6

Faraday’s Law states: the size of an induced EMF is proportional to the rate of change of magnetic flux cutting the conductor.

Question 7

Lenz’s Law states: {Definition}

Answer 7

Lenz’s Law states: that the direction of the induced EMF is always such as to oppose the change causing it. [a special case of the principle of conservation of energy]

Question 8

Mutual Induction is: {Definition}

Answer 8

Mutual Induction is: when the magnetic flux from a coil changes an EMF is induced in another coil.

Question 9

Self Induction is: {Definition}

Answer 9

Self Induction is: when the magnetic flux from a coil changes an EMF is induced in the same coil.