MCQGeeks
0 : 0 : 1
CBSE
JEE
NTSE
NEET
English
UK Quiz
Quiz
Driving Test
Practice
Games
Quiz
Electrical Engineering
Magnetic Circuit
Quiz 1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Q.1
The rate of rise of current through an inductive coil is maximum
At 63.2% of its maximum steady value
At the start of the current flow
After one time constant
Near the final maximum value of current
Q.2
The property of a material which opposes the creation of magnetic flux in it is known as
Reluctivity
Magneto-motive force
Permeance
Reluctance
Q.3
Conductivity is analogous to
Retentivity
Resistivity
Permeability
Inductance
Q.4
The relative permeability of a ferromagnetic material is
Less than one
More than one
More than 10
More than 100 Ωr 1000
Q.5
Energy stored by a coil is doubled when its current is increased by percent.
25
50.14
41.4
100
Q.6
Hard steel is suitable for making permanent magnets because
It has good residual magnetism
Its hysteresis loop has large area
Its mechanical strength is high
Its mechanical strength is low
Q.7
The unit of reluctance is
Meter/Henry
Henry/meter
Henry
1/Henry
Q.8
Hysteresis loss least depends on
Volume of material
Frequency
Steinmetz’s coefficient of material
Ambient temperature
Q.9
When both the inductance and resistance of a coil are doubled the value of
Time constant remains unchanged
Initial rate of rise of current is doubled
Final steady current is doubled
Time constant is halved
Q.10
Silicon steel is used in electrical machines because it has
Low coercivity
Low retentivity
Low hysteresis loss
High coercivity
Q.11
A ferrite core has less eddy current loss than an iron core because
Ferrites have high resistance
Ferrites are magnetic
Ferrites have low permeability
Ferrites have high hysteresis
Q.12
Conductance is analogous to
Permeance
Reluctance
Flux
Inductance
Q.13
Those magnetic materials are best suited for making armature and transformer cores which have ________permeability and _________hysteresis loss.
High, high
Low, high
High, low
Low, low
Q.14
The initial rate of rise of current through a coil of inductance 10 H when suddenly connected to a D.C. supply of 200 V is ___________Vs
50
20
0.05
500
Q.15
If the area of hysteresis loop of a material is large, the hysteresis loss in this material will be
Zero
Small
Large
None of the above
Q.16
The unit of retentivity is
Weber
Weber/sq. m
Ampere turn/meter
Ampere turns
Q.17
An air gap is usually inserted in magnetic circuits to
Increase m.m.f.
Increase the flux
Prevent saturation
None of the above
Q.18
Permanent magnets are normally made of
Alnico alloys
Aluminium
Cast iron
Wrought iron
Q.19
A material for good magnetic memory should have
Low hysteresis loss
High permeability
Low retentivity
High retentivity
Q.20
Reciprocal of reluctance is
Reluctivity
Permeance
Permeability
Susceptibility
0 h : 0 m : 1 s
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Report Question
×
What's an issue?
Question is wrong
Answer is wrong
Other Reason
Want to elaborate a bit more? (optional)
Support mcqgeeks.com by disabling your adblocker.
×
Please disable the adBlock and continue.
Thank you.
Reload page