Element of Electrical Design (3160918) MCQs

MCQs of GENERAL DESIGN ASPECTS

Showing 1 to 10 out of 84 Questions
1 2 3 4 5 6
1.

What is the unit of magnetic flux?

(a)

Weber
(b)

Henry
(c)

Ampere/metre
(d)

Ampere-turn/weber
Answer:

Option (a)

2.

What is the relative permeability of a vacuum?

(a)

 1
(b)

1 H/m
(c)

1/4
(d)

4π × 10-7 H/m
Answer:

Option (a)

3.

An air gap is usually inserted in a magnetic circuits to

(a)

Increase the flux
(b)

Increase m.m.f.
(c)

Prevent saturation
(d)

None of the these
Answer:

Option (c)

4.

Permeability in a magnetic circuit corresponds to ................in an electric circuit

(a)

Resistance
(b)

Conductance
(c)

Conductivity
(d)

Resistivity
Answer:

Option (c)

5.

Those magnetic materials are best suited for making armature and transform cores which have ...........permeability and ...........hysteresis loss

(a)

High, high
(b)

High, low
(c)

Low, high
(d)

 Low, low
Answer:

Option (b)

6.

In a magnetic material hysteresis loss takes place primarily due to

(a)

It high retentivity
(b)

Molecular friction
(c)

Flux density lagging behind the magnetising force
(d)

Rapid reversals of its magnetisation
Answer:

Option (a)

7.

The property of a material which opposes the creation of magnetic flux in it is known as

(a)

 Permeance
(b)

Reluctance
(c)

Magnetomotive force
(d)

Reluctivity
Answer:

Option (b)

8.

The area of hysteresis loss is a measure of

(a)

Magnetic flux
(b)

Energy loss per cycle
(c)

Permeance
(d)

Permittivity
Answer:

Option (b)

9.

In order to minimise hysteresis loss, the magnetic material should have

(a)

High retentivity
(b)

Large B - H loop area
(c)

Low hysteresis co-efficient
(d)

High resistivity
Answer:

Option (c)

10.

Hysteresis loss least depends on

(a)

Volume of material
(b)

Frequency
(c)

Steinmetz co-efficient of material
(d)

Ambient temperature
Answer:

Option (d)

Showing 1 to 10 out of 84 Questions
1 2 3 4 5 6