Electromagnetics Field (3140912) MCQs

MCQs of Magnetic forces, materials and inductance

Showing 101 to 110 out of 171 Questions
8 9 10 11 12 13
101.
Those materials are well suited for making permanent magnets which have______retentivity and _______coercivity.
(a) Low, high
(b) High, high
(c) High, low
(d) Low, low
Answer:

Option (b)

102.
If the area of hysteresis loop of a material is large, the hysteresis loss in this material will be
(a) Zero
(b) Small
(c) Large
(d) None of above
Answer:

Option (c)

103.
Hard steel is suitable for making permanent magnets because
(a) It has good residual magnetism
(b) Its hysteresis loop has large area
(c) Its mechanical strength is high
(d) Its mechanical strength is low
Answer:

Option (a)

104.
Silicon steel is used in electrical machines because it has
(a) Low coercivity
(b) Low retentivity
(c) Low hysteresis loss
(d) High coercivity
Answer:

Option (c)

105.
Conductance is analogous to
(a) Permeance
(b) Reluctance
(c) Flux
(d) Inductance
Answer:

Option (a)

106.
The property of a material which opposes the creation of magnetic flux in it is known as
(a) Reluctivity
(b) Magneto motive force
(c) Permeance
(d) Reluctance
Answer:

Option (d)

107.
The unit of retentivity is
(a) Weber
(b) Weber/m2
(c) Ampereturn/metre
(d) Ampereturn
Answer:

Option (a)

108.
Reciprocal of reluctance is
(a) Reluctivity
(b) Permeance
(c) Permeability
(d) Susceptibility
Answer:

Option (b)

109.
Flux in a magnetic circuit corresponds to______ in an electric circuit.
(a) Emf
(b) Current
(c) Current density
(d) Conductivity
Answer:

Option (b)

110.
The unit of reluctance is
(a) Henry
(b) Henry/metre
(c) metre/Henry
(d) Henry–1
Answer:

Option (d)

Showing 101 to 110 out of 171 Questions
8 9 10 11 12 13