Electricity and Magnetism Fundamentals MCQ
51. The ratio of the permeability of material to the permeability of air or vacuum.
- A. Relative permeability
- B. Relative permittivity
- C. Relative conductivity
- D. Relative reluctivity
Answer: Relative permeability
52. Permeance is analogous to
- A. Conductance
- B. Reluctance
- C. Admittance
- D. Resistance
Answer: Conductance
53. The property of magnetic materials of retaining magnetism after withdrawal of the magnetizing force is known as
- A. Retentivity
- B. Reluctivity
- C. Resistivity
- D. Conductivity
Answer: Retentivity
54. The quantity of magnetism retained by a magnetic material after withdrawal of the magnetizing force is called
- A. Leftover magnetism
- B. Hysteresis
- C. Residual magnetism
- D. Coercivity
Answer: Residual magnetism
55. The amount of magnetizing force to counter balance the residual magnetism of a magnetic material is referred to as
- A. Reluctivity
- B. Susceptivity
- C. Coercivity
- D. Retentivity
Answer: Coercivity
56. The ratio of the total flux (flux in iron path) to the useful flux (flux in air gap)
- A. Leakage flux
- B. Leakage current
- C. Leakage coefficient
- D. Leakage factor
Answer: Leakage factor
57. Defined as the number of lines per unit area through any substance in a plane at right angles to the lines of force
- A. Flux
- B. Flux lines
- C. Flux density
- D. Flux intensity
Answer: Flux density
58. Defined as the flux density produced in it due to its own induced magnetism
- A. Magnetic field intensity
- B. Electric field intensity
- C. Electromagnetic field intensity
- D. Intensity magnetization
Answer: Intensity magnetization
59. The force acting on a unit n- pole placed at that point is called
- A. Magnetic field intensity
- B. Electric field intensity
- C. Electromagnetic field intensity
- D. Intensity magnetization
Answer: Magnetic field intensity
60. The ratio between the intensity of magnetization produced in a substance to the magnetizing force producing it
- A. Magnetic Reluctivity
- B. Magnetic Resistivity
- C. Magnetic susceptibility
- D. Magnetic conductivity
Answer: Magnetic susceptibility
61. The lagging effect between flux density of the material and the magnetizing force applied
- A. Permeance
- B. Eddy current
- C. Hysteresis
- D. Reluctance
Answer: Hysteresis
62. Refers to the magnetic lines
- A. Flux
- B. Hysteresis
- C. Current
- D. Magnetomotive force
Answer: Flux
63. Refers to the non- metallic materials that have the ferromagnetic properties of iron.
- A. Ferrites
- B. Ferromagnetic
- C. Diamagnetic
- D. Paramagnetic
Answer: Ferrites
64. The air space between poles of magnets
- A. Air gap
- B. Free space
- C. Vacuum
- D. Atmosphere
Answer: Air gap
65. One that has magnetic poles produced by internal atomic structure with no external current necessary
- A. Diamagnetic
- B. Permanent magnets
- C. Paramagnetic
- D. Electromagnetic
Answer: Permanent magnets
66. Magnetic effects of the earth as a huge magnet with north and south poles.
- A. Diamagnetic
- B. Ferromagnetic
- C. Terrestrial magnetism
- D. Terrestrial ferromagnetism
Answer: Terrestrial magnetism
67. Used to maintain strength of magnetic field
- A. Container
- B. Air gap
- C. Keeper
- D. Source
Answer: Keeper
68. All magnetic field originates from
- A. moving electric charge
- B. Iron atoms
- C. Magnetic domain
- D. Permanent magnets
Answer: moving electric charge
69. Magnetic fields do not interact with
- A. Moving permanent magnets
- B. Stationary permanent magnets
- C. Moving electric charges
- D. Stationary electric charges
Answer: Stationary electric charges
70. The magnetic field inside a solenoid
- A. is zero
- B. is uniform
- C. increases with distance from the axis
- D. decreases with distance from the axis
Answer: is uniform
71. When the ferromagnetic substance is inserted in a current- carrying solenoid, the magnetic field is
- A. Greatly decreased
- B. Greatly increased
- C. Slightly decreased
- D. Slightly increased
Answer: Greatly increased
72. The magnetic field of a bar magnet most closely resembles the magnetic field of
- A. a horseshoe magnet
- B. a straight current- carrying wire
- C. a stream of electrons moving parallel to one another
- D. a current- carrying wire loop
Answer: a current- carrying wire loop
73. The magnetic field of a magnetized iron bar when strongly heated
- A. Becomes weaker
- B. Becomes stronger
- C. Reverses in direction
- D. is unchanged
Answer: Becomes weaker
74. A permanent magnet does not exert a force on
- A. an unmagnetized iron bar
- B. a magnetized iron bar
- C. a moving electric charge
- D. a stationary electric charge
Answer: a stationary electric charge
75. A current if flowing east along a power line. If the earth’s field is neglected, the direction of the magnetic field below it is
- A. North
- B. South
- C. East
- D. West
Answer: North
76. The emf produced in a wire by its motion across a magnetic field does not depend upon the
- A. Diameter of the wire
- B. Length of the wire
- C. Orientation of the wire
- D. Flux density of the field
Answer: Diameter of the wire
77. The induced emf in a wire loop that is moved parallel to a uniform magnetic field is
- A. Zero
- B. Dependent on the area of the loop
- C. Dependent on the shape of the loop
- D. Dependent on the magnitude of the field
Answer: Zero
78. When a wire loop is rotated in a magnetic field the direction of the induced emf changes one in every _______ revolution
- A. 1/3
- B. 1/2
- C. 1/4
- D. 2/3
Answer: 1/2
79. The magnetic flux through a wire loop in a magnetic field does not depend on
- A. The area of the loop
- B. The magnitude of the field
- C. The shape of the loop
- D. The angle between the plane of the loop and the direction
Answer: The shape of the loop
80. Steel is hard to magnetize because of its
- A. Low permeability
- B. High permeability
- C. High density
- D. High retentivity
Answer: Low permeability
81. Paramagnetic substance has a relative permeability of
- A. Slightly less than one
- B. Equal to one
- C. Slightly equal to one
- D. Very much greater than one
Answer: Slightly equal to one
82. A group of magnetically aligned atoms is called
A. RangeB. Lattice
C. Domain
D. Crystal
Answer: Domain
83. The force between two magnetic poles varies with the distance between them. The variation is ______ to the square of that distance.
- A. Equal
- B. Greater than
- C. Directly proportional
- D. Inversely proportional
Answer: Inversely proportional
84. Permeability means
- A. The conductivity of the material for magnetic lines of force
- B. The magnetization test in the material after exciting field has been removed
- C. The strength of an electromagnet
- D. The strength of the permanent magnet
Answer: The conductivity of the material for magnetic lines of force
85. ______ is an electromagnet with its core in the form of a close magnetic ring.
- A. Solenoid
- B. Paraboloid
- C. Toroid
- D. Cycloid
Answer: Toroid
86. A magnetic material losses its ferromagnetic properties at a point called
- A. Curie temperature
- B. Inferred absolute temperature
- C. Room temperature
- D. Absolute temperature
Answer: Curie temperature
87. Small voltages generated by a conductor with current in an external magnetic field.
- A. Skin effect
- B. Magnetic effect
- C. Hall effect
- D. Flywheel Effect
Answer: Hall effect
88. The emission of electrons from hot bodies is called
- A. Radiation effect
- B. Edison effect
- C. Skin effect
- D. Half effect
Answer: Edison effect
89. The ability of a mechanically stressed ferromagnetic wire to recognize rapid switching of magnetization when subjected to a dc magnetic field.
- A. Wartheim effect
- B. Wiedemann effect
- C. Wiegand effect
- D. Edison effect
Answer: Wiegand effect
90. An effect which is generally used in the gausameter to measure flux density.
- A. Skin effect
- B. Magnetic effect
- C. Hall effect
- D. Flywheel effect
Answer: Hall effect
91. The contribution to the ionization in an ionization chamber by electrons liberated from the walls.
- A. Skin effect
- B. Walt effect
- C. Hall effect
- D. Edison effect
Answer: Walt effect
92. The tiniest element of matter
- A. Atom
- B. Proton
- C. Electron
- D. Neutron
Answer: Atom
93. All matters (gas, liquid and solid) are composed of
- A. Neutrons
- B. Particles
- C. Electrons
- D. Atoms
Answer: Atoms
94. The simplest type of atom to exist is the ______ atom.
- A. Helium
- B. Hydrogen
- C. Boron
- D. Oxygen
Answer: Hydrogen
95. What revolves about the positive nucleus in a definite orbit?
- A. Atom
- B. Proton
- C. Electron
- D. Neutron
Answer: Electron
96. The uncharged particles which have no effect on its atomic charge.
- A. Nucleons
- B. Electrons
- C. Protons
- D. Neutrons
Answer: Neutrons
97. The diameter of a hydrogen atom is approximately ______ cm.
- A. 1.1 x 10-6
- B. 1.1 x 10-7
- C. 1.1 x 10-8
- D. 1.1 x 10-9
Answer: 1.1 x 10-8
98. The K shell or the first shell has how many permissible number of orbiting electrons?
- A. 1
- B. 2
- C. 3
- D. 4
Answer: 2
99. Germanium atom has ______ protons and ______ electrons.
- A. 32, 32
- B. 32, 42
- C. 42, 32
- D. 34, 34
Answer: 32, 32
100. A germanium atom has an atomic weight of 72. How many neutrons are there?
- A. 32
- B. 40
- C. 34
- D. 36
Answer: 40
