Module 6 Chapter 3 - Electromagnetism

Question 1

What is the most basic equation for calculating magnetic flux over an area (ɸ)? (it has θ in it)

Answer 1

ɸ = BACos(θ), where B is the magnetic flux density and A is the area over which the magnetic flux is.

Question 2

Which finger for Fleming’s left hand rule shows the direction of current?

Answer 2

The second finger shows the direction of current.

Question 3

How does one calculate the magnitude of a force acting on a wire in a magnetic field?

Answer 3

F = BILSin(θ)

Question 4

What is the equation for calculating the force acting on a charged particle moving perpendicular to a magnetic field?

Answer 4

F = BQv (note this is derived fairly trivially from F = BIL)

Question 5

How does Fleming’s right hand rule work relative to the left hand rule?

Answer 5

Fleming’s right hand rule is used to work out the inverse of the left hand rule; each digit is the same variable, but it calculates the induced current from movement instead of induced force from current.

Question 6

What is the equation that combines Faraday’s law and Lenz’s law?

Answer 6

ε = -Δ (Nɸ) / Δt

Question 7

What is the equation that relates the potential difference to the number of turns of two transformers?

Answer 7

nₛ / nₚ = Vₛ / Vₚ