electromagnetism

Question 1

cross and dot

Answer 1

cross = going into paper
dot = coming out of paper

Question 2

When is F= BIL maximum

Answer 2

Maximum when wire is perpendicular to field
When wire is parallel to field there will be no force as sin(0) = 0

Question 3

Flemings left hand rule components

Answer 3

Thumb- motion, force
First finger- field
SeCond finger - current

Question 4

Difference between magnetic flux density and magnetic flux

Answer 4

Magnetic flux = the amount of magnetic field passing through a given area
Magnetic flux density = (how strong/ concentrated the magnetic flux is) strength of magnetic field at a specific point in space

Magnetic flux has units of Wb
Magnetic flux density has units of tesla

Question 5

Faradays Law
why is it negative

Answer 5

Emf ∝ rate of change of magnetic flux linkage
The induced Coil turns into a north pole which repels the north pole of the magnetic

Question 6

Lenz’ Law

Answer 6

The direction of the induced current is so as to oppose the charge producing it
This occurs as if the pole induced was a south pole the magnet would accelerate through it and energy will not be conserved

Question 7

How do transformers work

Answer 7

Soft iron core
Alternating current attached to a coil
The AC current produces a rate of change of magnetic flux linkage
Soft iron core links the primary coil to the secondary one
Emf is induced in the secondary coil due to faradays law