The direction of rotation of an hysteresis motor is determined by

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 the above

In repulsion motor direction of rotation of motor

A

Is opposite to that of brush shift

B

Is the same as that of brush shift

C

Is independent of brush shift

D

None

In case of a shaded pole motor the direction of rotation of the motor is

A

from main pole to shaded pole

B

from shaded pole to main pole

C

either of the above depending on voltage

D

either of the above depending on power factor

A hysteresis motor works on the principle of

A

hysteresis loss

B

magnetisation of rotor

C

eddy current loss

D

electromagnetic induction

In a hysteresis motor, the rotor must have

A

retentivity

B

resistivity

C

susceptibility

D

none of the above

Which of the following statements regarding hysteresis motor is in incorrect ?

A

It is extremely sensitive to fluctuations in supply voltage

B

Its high starting torque is due to its high rotor hysteresis loss

C

It is extremely quiet in operation

D

It accelerates from rest to full-speed almost instantaneously

Hysteresis motor is particularly useful for high-quality record players and tape-recorders because

A

it revolves synchronously

B

it is not subject to any magnetic or mechanical vibrations

C

it can be easily manufactured in extremely small sizes of up to 1 W output

D

it develops hysteresis torque which is extremely steady both in amplitude and phase

The rotor of a hysteresis motor is made of

A

aluminium

B

cast iron

C

chrome steel

D

copper

Which of the following law/rule can he used to determine the direction of rotation of D.C. motor?

A

Lenz

B

Faraday

C

Coulomb’s law

D

Fleming

The direction of rotation of a D.C. series motor can be changed by

A

Interchanging supply terminals

B

Interchanging field terminals

C

Either of (A) and (B) above

D

None of the above

The direction of rotation of an hysteresis motor is determined by

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