Ch20 Electromagnetic Forces

Question 1

Define right-hand grip rule:

Answer 1

A rule which gives the direction of field lines around a straight wire when it flows through it

Question 2

Define armature:

Answer 2

The moving part of an electromagnetic device such as relay/bell

Question 3

Define motor effect:

Answer 3

When current flows in a wire
in a magnetic field which is not parallel to the current,
a force is exerted on the wire

Question 4

Define Flemings left-hand rule:

Answer 4

A rule that gives the relationship
between the directions of force, field and current
when current flows across the magnetic field

Question 5

Define commutator:

Answer 5

A dvice used to allow current to flow to and from the coil of a d.c. motor/generator

Question 6

What is a motor?

Answer 6

A device that transfers energy by an electrical current into a mechanical (kinetic) energy store

Question 7

What is an electrical generator?

Answer 7

(Does the opposite asa motor)

Transfers energy from a mechanical energy store by an electrical current

Can be used in reverse to generate electricity