Deck 1: Electric Induction Theory

Question 1

What is the difference between resistance and reactance?

Answer 1

Resistance is a physical property of every electrical conductor, which restricts or opposes the flow of electrical current.It can be read with an ohmmeter and when current flows through resistance, heat is dissipated and there is a power loss.Reactance is an opposition to current flow in an electrical circuit that prevents the current's flow in the first place.It cannot be measured with an ohmmeter and needs to be calculated.There are no power losses or head loss because it prevents current from happening.

Question 2

The term ____ means that there is only one wire coil that both the principle of electro-magnetism and the principle of electro-magnetic induction act on..

A)mutual induction
B)conductor
C)self-induction
D)ampere

Answer 2

C

Question 3

A coil of wire is a series circuit, meaning that the current flow would be ____ throughout the entire coil, and so would the magnetic behaviors associated with current flow.

A)opposite
B)the same throughout
C)increased
D)negative

Answer 3

B

Question 4

The principle of electro-magnetism states that electrical current flows through an electrical ____, a magnetic field will be created.

A)insulator
B)conductor
C)line of flux
D)electron

Question 5

The principle of electro-magnetism states that when an electrical current flows through an electrical conductor, a magnetic field will be created around that conductor.

Question 6

The greater the magnetic flux density, the lower the induced voltage will be.

Question 7

The term ____ is a common term used to describe that the strength of the electro-magnetic field is determined by the number of wire turns in the coil, and the intensity of current flow through the coil.

A)permeability
B)electro-magnet
C)ampere-turns
D)inductor

Question 8

Mutual induction is when more than one inductor coil is mounted on a common ____ core.

A)copper
B)air
C)gold
D)iron

Question 9

"Opposing a change in current" means the inductors will ____ the current flow through the inductor.

A)stabilize
B)prevent
C)block
D)reverse

Question 10

Resistance and ____________________ are two properties in an inductor that oppose current flow.

Question 11

Lenz's Law states that an induced voltage will be the opposite polarity as the electrical source voltage that created it.

Question 12

Ohm's Law verifies that voltage and current are ____ in a resistive circuit.

A)directly proportional
B)inversely proportional
C)not related
D)equal

Question 13

Describe Lenz's Law.

Question 14

____________________ is the difference in time between when the voltage was applied to the inductor coil and current started to flow through the coil.

Question 15

The magnetic polarity of an electromagnetic field is determined by the direction of current flow through the coil.

Question 16

CEMF (counter electro-motive force) is sometimes called counter ____________________.

Question 17

The strength of the magnetic field created by an electromagnet is determined by the magnetic polarity.

Question 18

When an inductor coil is energized with a source voltage, the voltage will distribute itself across all the wire turns of the energized coil is called ____.

A)magnetic lines of flux
B)volts-per-turn principle
C)relative motion
D)electro-magnetic induction

Question 19

The three properties that determine the strength of any electro-magnet are intensity of current flow, number of wire turns in the coil and ____.

A)type of core material
B)circuit
C)magnetic field
D)voltage

Question 20

Three factors that are required to be present for electro-magnetic induction to occur are an electrical conductor, magnetic lines of flux and ____.

A)relative motion between the two
B)turns of wire
C)current flow
D)magnetic field