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Free download in PDF Inductance Objective Type Questions and Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams. These short solved questions or quizzes are provided by Gkseries.
(21)
The direction of induced e.m.f. can be found by
[A]
Laplace’s law
[B]
Lenz’s law
[C]
Fleming’s right hand rule
[D]
Kirchhoff s voltage law
(22)
If current in a conductor increases then according to Lenz’s law self-induced voltage will
[A]
produce current opposite to the in-creasing current
[B]
aid the applied voltage
[C]
tend to decrease the amount of cur-rent
[D]
aid the increasing current
Answer: produce current opposite to the in-creasing current
(23)
Both the number of turns and the core length of an inductive coil are doubled.
Its self-inductance will be
[A]
doubled
[B]
halved
[C]
quadrupled
[D]
unaffected
(24)
An open coil has
[A]
infinite resistance and zero inductance
[B]
infinite resistance and normal inductance
[C]
zero resistance and inductance
[D]
zero resistance and high inductance
Answer: infinite resistance and zero inductance
(25)
In an iron cored coil the iron core is removed so that the coil becomes an air cored coil. The inductance of the coil will
[A]
remain the same
[B]
increase
[C]
decrease
[D]
initially increase and then decrease
(26)
Higher the self-inductance of a coil,
[A]
longer the delay in establishing steady current through it
[B]
greater the flux produced by it
[C]
lower the e.m.f. induced
[D]
lesser its weber-turns
Answer: longer the delay in establishing steady current through it
(27)
The inductance of a coil will increase under all the following conditions except
[A]
when more length for the same number of turns is provided
[B]
when the number of turns of the coil increase
[C]
when more area for each turn is provided
[D]
when permeability of the core increases
Answer: when more length for the same number of turns is provided
(28)
Which of the following circuit element stores energy in the electromagnetic field ?
[A]
Inductance
[B]
Resistance
[C]
Variable resistor
[D]
Condenser
(29)
As per Faraday’s laws of electromagnetic induction, an e.m.f. is induced in a conductor whenever it
[A]
moves parallel to the direction of the magnetic field
[B]
cuts magnetic flux
[C]
lies perpendicular to the magnetic flux
[D]
lies in a magnetic field
Answer: cuts magnetic flux
(30)
The property of coil by which a counter e.m.f. is induced in it when the current through the coil changes is known as
[A]
self-inductance
[B]
mutual inductance
[C]
series aiding inductance
[D]
capacitance
31
The four factors determining inductance are the number of turns, coil length, coil area, and:
[A]
permeability
[B]
reluctance
[C]
counter emf
[D]
coefficient of coupling
32
What is the number of turns required in the secondary winding for a transformer when 120 volts is applied to a 2400-turn primary to produce 7.5 Vac at the secondary?
[A]
150 turns
[B]
1920 turns
[C]
900 turns
[D]
75 turns
33
Which two values are plotted on a B-H curve graph?
[A]
flux density and magnetizing force
[B]
magnetizing force and permeability
[C]
permeability and reluctance
[D]
reluctance and flux density
Answer: flux density and magnetizing force
34
A magnetic field has:
[A]
lines of force
[B]
magnetomotive force
[C]
polar fields
[D]
lines of reluctance
35
Electromagnetism is the:
[A]
current in the coil
[B]
action between a permanent and an artificial magnet
[C]
magnetic field action with a current-carrying wire
[D]
magnetic field caused by a permanent magnet
Answer: magnetic field action with a current-carrying wire
36
What is the permeability of transformer iron?
[A]
5,500
[B]
1,500
[C]
450
[D]
50
37
The polarity of induced voltage while a field is collapsing is:
[A]
opposite to the force creating it
[B]
independent of the force creating it
[C]
identical to the force creating the field
[D]
present only if the force is stationary
Answer: opposite to the force creating it
38
What does Faraday's law concern?
[A]
a magnetic field cutting a conductor
[B]
a magnetic field in a conductor
[C]
a magnetic field in a coil
[D]
a magnetic field hystersis
Answer: a magnetic field cutting a conductor
39
A henry value divided by a circuit resistive value provides the:
[A]
induced voltage amplitude
[B]
quality factor of the coil
[C]
counter emf value
[D]
rise or decay time constant
Answer: induced voltage amplitude
40
Faraday's law states that the:
[A]
emf depends on the rate of cutting flux
[B]
emf is related to the direction of the current
[C]
direction of an induced current produces an aiding effect
[D]
direction of the induced voltage produces an opposition
Answer: emf depends on the rate of cutting flux
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