ELECTRONICS AND COMMUNICATION ENGINEERING IMPORTANT MCQ-ELECTRICITY AND MAGNETISM FUNDAMENTALS (PART TWO)

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 
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
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
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 
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

61.  The lagging
effect between flux density of the material and the magnetizing force applied

A.  Permeance
        B.  Eddy current
        C.  Hysteresis
D.  Reluctance

62.  Refers
to the magnetic lines

      A. Flux

        B.  Hysteresis

        C.  Current

      D.  Magnetomotive force
63.  Refers
to the non- metallic materials that
have the ferromagnetic properties of iron.
      A.
Ferrites

        B.  Ferromagnetic

        C.  Diamagnetic

      D.  Paramagnetic
64.  The
air space between poles of magnets
       A. Air
gap

         B.  Free space

 C.  Vacuum 
       D.  Atmosphere
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
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
67.  Used to
maintain strength of magnetic field

A.  Container

         B.  Air gap

C.  Keeper

D.  Source

 68.  All
magnetic field originates from
      A. moving electric charge

        B.  Iron atoms

        C.  Magnetic domain

      D.  Permanent magnets
69.  Magnetic  fields do not interact with

A.  Moving
permanent magnets

         B.  Stationary
permanent magnets

C.  Moving   electric  
charges
D. 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
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
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
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

 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

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
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
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
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
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

80.  Steel
is hard to magnetize because of its

         A. Low permeability

         B.  High permeability
         C.  High density
 D.  High retentivity

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 
82.  A group of
magnetically aligned atoms is  called
 A.  Range
         B.  Lattice
         C.  Domain
D.  Crystal
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
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
85.               is an
electromagnet with its core in the
form of a close magnetic  ring.
A.  Solenoid
        B.  Paraboloid
        C.  Toroid
D.  Cycloid

 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
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
88.  The emission
of electrons from hot bodies is called

 A.  Radiation effect

         B.  Edison effect

C.  Skin effect 
D.  Half 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
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
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

92.  The
tiniest element of matter

        A. Atom
        B.  Proton
        C.  Electron
      D.  Neutron
93. All matters
(gas, liquid and solid) are composed  of
A.  Neutrons
        B.  Particles
C.  Electrons
D. Atoms
94.  The simplest
type of atom to exist is the             atom.
 A.  Helium
         B.  Hydrogen
         C.  Boron
D.  Oxygen
95.  What revolves
about the positive nucleus in a
definite  orbit?
A.  Atom
         B.  Proton
         C.  Electron
       D.  Neutron
96.  The uncharged
particles which have no effect on
its atomic  charge.
A.  Nucleons
        B.  Electrons
C.  Protons 
D. 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

 98.  The K shell or
the first shell has how many
permissible number of orbiting  electrons?

 A.  1

         B.  2
         C.  3
D.  4
 99.  Germanium atom has             protons and              electrons.
A. 32,
32

B.
32, 42
C.
42, 32
D.
34, 34
100.  A germanium
atom has an atomic weight of 72. How many neutrons are  there?
A.  32
B.  40
C.  34
        D.  36
101.   How many
neutrons does a copper atom have?
A.  32
B.  33
C.  34
D.  29
102. Bonding
of atoms that is due to the force of
attraction between positive ions and a group of negative ions
A.  Ionic bond
B.  Covalent Bond
C.  Electrostatic
Bond 
D. Metallic bond
103. An
alloy of 22 percent iron and 78 per cent nickel.
        A. Permalloy
B.  Alnico
C.  Constantan
D.  Manganin

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