Electromagnetic Induction

Question 1

definition of magnetic flux?

Answer 1

Magnetic flux is the product of an area and the component of the magnetic flux density perpendicular to that area
(basically just the formula)

Question 2

Formula for magnetic flux?

Answer 2

Φ = BAcosθ, unit = Wb (weber)

again, θ is the angle between the normal and the magnetic flux (look at the angle between the arrowheads)

Question 3

definition of a weber?

Answer 3

1 weber is the magnitude of magnetic flux through an area of 1m^2 when a magnetic field of 1T acts perpendicularly into the area.

Question 4

definition of magnetic flux linkage?

Answer 4

it is defined as the product of the number of turns, N, of the coil and the magnetic flux passing through the coil.

Question 5

formula for magnetic flux linkage?

Answer 5

NΦ = NBAcosθ

Question 6

What is Faraday’s Law of Electromagnetic Induction?

Answer 6

It states that the magnitude of the induced emf in a conductor is directly proportional to the rate of change of the magnetic flux linkage.

aka: E = - dNBAcosθ / dt

Question 7

What is Lenz’s Law?

Answer 7

Lenz’s Law states that the direction of the induced emf is such that it may produce an effect that opposes the change causing it.

Question 8

What is another formula for induced emf?

Answer 8

E = Blv

this is used when theres like a rod moving and reducing the area yes

Question 9

for Faraday’s Paradox, what is the equation for induced emf? aka the spinning disk thingy

Answer 9

E = Bπr^2f

Question 10

formulas for magnetic flux linkage and induced emf in an AC generator? (in terms of t)

Answer 10

Φ = NBAcosωt
differentiate
E = NBAωsinωt

Question 11

what is the same in a transformer? (EMI APQ MCQ Q1)

Answer 11

the magnetic flux in the transformer (and in both primary and secondary coil) is the same.