Question 1

The magnetizing force H) is not dependent on which of following?

Accepted Answer

A)  the length of the material 
B)  the number of turns 
C)  the type of material 
D)  the amount of current flow 
A)  the length of the material 
B)  the number of turns 
C)  the type of material 
D)  the amount of current flow

Question 2

Unlike magnetic poles attract each other, and like magnetic poles repel each other.

Accepted Answer

A) True 
 B)False

Question 3

The opposition to magnetic flux line flow is called:

Accepted Answer

A)  retention 
B)  reluctance 
C)  Webers per meter 
D)  permeability. 
A)  retention 
B)  reluctance 
C)  Webers per meter 
D)  permeability.

Question 4

The most common movement for analog meters is the:

Accepted Answer

A)  electrodynamometer 
B)  d'Arsonval movement 
C)  iron-vane movement 
D)  hot wire movement 
A)  electrodynamometer 
B)  d'Arsonval movement 
C)  iron-vane movement 
D)  hot wire movement

Question 5

Calculate the reluctance of a 4-meter long toroidal coil made of low-carbon steel with an inner radius of 1.75 cm and an outer radius of 2.25 cm. The permeability of the steel is 2 × 10-4 Wb/At - m.

Accepted Answer

A)  2.29 × 106 At/Wb 
B)  4.03 × 105 At/Wb 
C)  1.96 × 10-5 At/Wb 
D)  31.9 × 106 At/Wb 
A)  2.29 × 106 At/Wb 
B)  4.03 × 105 At/Wb 
C)  1.96 × 10-5 At/Wb 
D)  31.9 × 106 At/Wb

Question 6

A permanent magnet is basically a coil of wire wound around a magnetic core.

Accepted Answer

A) True 
 B)False

Question 7

Ferrites are:

Accepted Answer

A)  low electrical resistance, high permeability materials. 
B)  high electrical resistance, high permeability materials. 
C)  paramagnetic materials. 
D)  diamagnetic materials. 
A)  low electrical resistance, high permeability materials. 
B)  high electrical resistance, high permeability materials. 
C)  paramagnetic materials. 
D)  diamagnetic materials.

Question 8

Materials that can be magnetized are called ferromagnetic.

Accepted Answer

A) True 
 B)False

Question 9

Magnetizing force "H," is measured in:

Accepted Answer

A)  ampere-turns per meter 
B)  ampere-turns per Weber. 
C)  number of turns per square meter 
D)  Webers per square meter. 
A)  ampere-turns per meter 
B)  ampere-turns per Weber. 
C)  number of turns per square meter 
D)  Webers per square meter.

Question 10

The symbol for flux density is:

Accepted Answer

A)  O 
B)  A 
C)  B 
D)  T 
A)  O 
B)  A 
C)  B 
D)  T

Question 11

Magnetic flux lines are never continuous outside of the magnet.

Accepted Answer

A) True 
 B)False

Question 12

An example of an electromagnetic device is:

Accepted Answer

A)  the relay 
B)  a tape recording head 
C)  the loudspeaker 
D)  the solenoid 
E)  all of the above 
A)  the relay 
B)  a tape recording head 
C)  the loudspeaker 
D)  the solenoid 
E)  all of the above

Question 13

Induced voltage is directly proportional to the relative motion between a conductor and a magnetic field.

Accepted Answer

A) True 
 B)False

Question 14

Which of the following statements about flux lines is not correct?

Accepted Answer

A)  They are continuous. 
B)  They never cross each other. 
C)  Magnetic flux flows from the north pole to the south pole within the magnet. 
D)  They flow in the shortest and/or easiest path. 
A)  They are continuous. 
B)  They never cross each other. 
C)  Magnetic flux flows from the north pole to the south pole within the magnet. 
D)  They flow in the shortest and/or easiest path.

Question 15

The amount of magnetomotive force is inversely proportional to the amount of current flow.

Accepted Answer

A) True 
 B)False

Question 16

What is the mmf of a material whose magnetic flux is equal to 670 microwebers with a reluctance of
44.8 × 103 At/Wb?

Accepted Answer

A)  30 At 
B)  20 At 
C)  40 At 
D)  10 At 
A)  30 At 
B)  20 At 
C)  40 At 
D)  10 At

Question 17

Magnetic flux lines travel from:

Accepted Answer

A)  north to south inside the magnet 
B)  north to south outside the magnet. 
C)  south to north outside the magnet 
D)  higher flux areas to lower flux areas 
A)  north to south inside the magnet 
B)  north to south outside the magnet. 
C)  south to north outside the magnet 
D)  higher flux areas to lower flux areas

Question 18

The  S.I. is the unit of magnetic flux.

Accepted Answer

A)  Maxwell 
B)  Weber 
C)  Tesla 
D)  reluctance 
A)  Maxwell 
B)  Weber 
C)  Tesla 
D)  reluctance

Question 19

If the current flow was visualized going into this page, the magnetic field would be drawn clockwise around the conductor.

Accepted Answer

A) True 
 B)False

Question 20

Permanent magnets are characterized by the fact that:

Accepted Answer

A)  they lose their magnetism very quickly. 
B)  they produce an electrostatic field. 
C)  their magnetic domains are aligned north-to-south. 
D)  their magnetic domains are randomly oriented. 
A)  they lose their magnetism very quickly. 
B)  they produce an electrostatic field. 
C)  their magnetic domains are aligned north-to-south. 
D)  their magnetic domains are randomly oriented.

Exam 10: Magnetism and Electromagnetism

The magnetizing force H) is not dependent on which of following?

Unlike magnetic poles attract each other, and like magnetic poles repel each other.

The opposition to magnetic flux line flow is called:

The most common movement for analog meters is the:

Calculate the reluctance of a 4-meter long toroidal coil made of low-carbon steel with an inner radius of 1.75 cm and an outer radius of 2.25 cm. The permeability of the steel is 2 × 10-4 Wb/At - m.

A permanent magnet is basically a coil of wire wound around a magnetic core.

Ferrites are:

Materials that can be magnetized are called ferromagnetic.

Magnetizing force "H," is measured in:

The symbol for flux density is:

Magnetic flux lines are never continuous outside of the magnet.

An example of an electromagnetic device is:

Induced voltage is directly proportional to the relative motion between a conductor and a magnetic field.

Which of the following statements about flux lines is not correct?

The amount of magnetomotive force is inversely proportional to the amount of current flow.

What is the mmf of a material whose magnetic flux is equal to 670 microwebers with a reluctance of 44.8 × 103 At/Wb?

Magnetic flux lines travel from:

The S.I. is the unit of magnetic flux.

If the current flow was visualized going into this page, the magnetic field would be drawn clockwise around the conductor.

Permanent magnets are characterized by the fact that:

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