Question 1

Which one of the statements below does NOT apply to the voltage induced into a wire when it is moved through a magnetic field?

Accepted Answer

A) It depends on the length of moving wire in the field. 
B) It depends on the strength of the magnetic field. 
C) It depends on the speed of wire motion. 
D) It depends on the current flowing in the wire. 
A) It depends on the length of moving wire in the field. 
B) It depends on the strength of the magnetic field. 
C) It depends on the speed of wire motion. 
D) It depends on the current flowing in the wire. D

Question 2

An iron core electromagnet has a higher ________ than an air core electromagnet.

Accepted Answer

A) current 
B) permeability 
C) resistance 
D) reactance 
A) current 
B) permeability 
C) resistance 
D) reactance B

Question 3

Induced voltage resulting from electromagnetic induction is proportional to:

Accepted Answer

A) the rate at which the conductor and magnetic fields move relative to each other. 
B) the angle at which the conductor cuts the magnetic field. 
C) the number of turns of wire in the coil. 
D) all of these. 
A) the rate at which the conductor and magnetic fields move relative to each other. 
B) the angle at which the conductor cuts the magnetic field. 
C) the number of turns of wire in the coil. 
D) all of these. D

Question 4

Permeability is ________.

Accepted Answer

A) the shielding effect of a material 
B) the opposition to being magnetized 
C) the ease of a material to be magnetized 
D) the ability of a magnetic material to conduct a current 
A) the shielding effect of a material 
B) the opposition to being magnetized 
C) the ease of a material to be magnetized 
D) the ability of a magnetic material to conduct a current

Question 5

Unlike magnetic poles ________ and like poles ________.

Accepted Answer

A) attract, attract 
B) repel, repel 
C) attract, repel 
D) repel, attract 
A) attract, attract 
B) repel, repel 
C) attract, repel 
D) repel, attract

Question 6

A solenoid consists of ________.

Accepted Answer

A) a coil of wire wound around a core 
B) a permanent magnet 
C) a burglar alarm relay 
D) two plates separated by an insulator 
A) a coil of wire wound around a core 
B) a permanent magnet 
C) a burglar alarm relay 
D) two plates separated by an insulator

Question 7

Two north magnetic poles attract one another.

Accepted Answer

A) True 
 B)False

Question 8

Flux lines are concentrated at the center of a magnet.

Accepted Answer

A) True 
 B)False

Question 9

A coil of wire with current flowing through it is called a(n) ________.

Accepted Answer

A) north pole 
B) south pole 
C) capacitor 
D) electromagnet 
A) north pole 
B) south pole 
C) capacitor 
D) electromagnet

Question 10

A relay is a device that ________.

Accepted Answer

A) isolates the actuating signal from the control signal 
B) has a coil to actuate some contacts that control other circuits 
C) uses an electromagnet to open and close contacts 
D) all of these 
A) isolates the actuating signal from the control signal 
B) has a coil to actuate some contacts that control other circuits 
C) uses an electromagnet to open and close contacts 
D) all of these

Question 11

The permeability of air is ________.

Accepted Answer

A) 19.2 
B) 1 
C) 7 
D) 22 
A) 19.2 
B) 1 
C) 7 
D) 22

Question 12

If some turns of wire are removed from an electromagnet, the magnetic field will ________.

Accepted Answer

A) be more than the original electromagnet 
B) be the same as the original electromagnet 
C) be less than the original electromagnet 
A) be more than the original electromagnet 
B) be the same as the original electromagnet 
C) be less than the original electromagnet

Question 13

If a relay picks up and makes a contact but does not stay picked up, whatʹs the trouble?

Accepted Answer

A) The relay coil is open. 
B) The magnetic field is too strong. 
C) The magnetic field is too weak. 
D) There is no trouble. The relay is operating normally. 
A) The relay coil is open. 
B) The magnetic field is too strong. 
C) The magnetic field is too weak. 
D) There is no trouble. The relay is operating normally.

Question 14

The opposition to being magnetized is called permeability.

Accepted Answer

A) True 
 B)False

Question 15

The polarity of an induced voltage depends on the ________.

Accepted Answer

A) length of a conductor in a magnetic field 
B) time that the conductor remains stationary in a magnetic field 
C) direction of motion of a conductor in a magnetic field 
D) amount of current flowing 
A) length of a conductor in a magnetic field 
B) time that the conductor remains stationary in a magnetic field 
C) direction of motion of a conductor in a magnetic field 
D) amount of current flowing

Question 16

A simple electric doorbell probably uses ________ to ring the bell.

Accepted Answer

A)    switch 
B) an electromagnet 
C) transistor 
D) a permanent magnet 
A)    switch 
B) an electromagnet 
C) transistor 
D) a permanent magnet

Question 17

If more turns of wire are added to a coil and then that coil is moved through a magnetic field, the voltage produced will ________.

Accepted Answer

A) be the same as the original coil 
B) be more than the original coil 
C) be less than the original coil 
A) be the same as the original coil 
B) be more than the original coil 
C) be less than the original coil

Question 18

Soft iron has a high ________.

Accepted Answer

A) reactance 
B) resistance 
C) permeability 
D) mmf 
A) reactance 
B) resistance 
C) permeability 
D) mmf

Question 19

Soft iron, copper, and silver make good magnets.

Accepted Answer

A) True 
 B)False

Question 20

According to the left-hand rule for the magnetic field around a conductor, what points in the direction of current flow?

Accepted Answer

A) meter 
B) index finger 
C) thumb 
D) fingers 
A) meter 
B) index finger 
C) thumb 
D) fingers

Exam 7: Series-Parallel Circuits

Which one of the statements below does NOT apply to the voltage induced into a wire when it is moved through a magnetic field?

An iron core electromagnet has a higher ________ than an air core electromagnet.

Induced voltage resulting from electromagnetic induction is proportional to:

Permeability is ________.

Unlike magnetic poles ________ and like poles ________.

A solenoid consists of ________.

Two north magnetic poles attract one another.

Flux lines are concentrated at the center of a magnet.

A coil of wire with current flowing through it is called a(n) ________.

A relay is a device that ________.

The permeability of air is ________.

If some turns of wire are removed from an electromagnet, the magnetic field will ________.

If a relay picks up and makes a contact but does not stay picked up, whatʹs the trouble?

The opposition to being magnetized is called permeability.

The polarity of an induced voltage depends on the ________.

A simple electric doorbell probably uses ________ to ring the bell.

If more turns of wire are added to a coil and then that coil is moved through a magnetic field, the voltage produced will ________.

Soft iron has a high ________.

Soft iron, copper, and silver make good magnets.

According to the left-hand rule for the magnetic field around a conductor, what points in the direction of current flow?

Quantities and Units

Voltage, Current, and Resistance

Ohms Law

Energy and Power

Series Circuits

Parallel Circuits

Circuit Theorems and Conversions

Branch, Loop, and Node Analyses

Magnetism and Electromagnetism

Introduction to Alternating Current and Voltage

Capacitors

Inductors

Transformers

RC Circuits

RL Circuits

RlC Circuits and Resonance

Passive Filters

Circuit Theorems in Ac Analysis

Time Response of Reactive Circuits

Three-Phase Systems in Power Applications

Filters

Unlike magnetic poles and like poles .