Chapter 4: Electromagnetism

Question 1

Catapult field

Answer 1

Resultant magnetic field produced by the interaction between the
magnetic field from a current-carrying conductor and the magnetic field
from a permanent magnet

Question 2

Magnetic field

Answer 2

A region in the surrounding of a magnet which a magnetic material
experiences a detectable force

Question 3

Electromagnetic
induction

Answer 3

Production of an induced e.m.f. in a conductor when there is relative
motion between the conductor and a magnetic field or when the
conductor is in a changing magnetic field

Question 4

Induced current

Answer 4

The current produced when there is the change in magnetic flux

Question 5

Lenz’s law

Answer 5

The induced current always flow in a direction that opposes the change of magnetic flux that causes it

Question 6

Faraday’s law

Answer 6

The magnitude of induced e.m.f. is directly proportional to the rate of
cutting of magnetic flux

Question 7

Transformer

Answer 7

An electrical device which increases or decreases an alternating voltage
based on the principle of electromagnetic induction

Question 8

Step-up transformer

Answer 8

Trasformer that is used to increase the voltage

Question 9

Step-down transformer

Answer 9

Transformer that is used to decrease the voltage

Question 10

Ideal transformer

Answer 10

Transformer that does not experience any loss of energy, that is the
efficiency, n is 100%