For driving high inertia loads best type of induction motor suggested is

A wound rotor induction motor is preferred, as compared to squirrel cage induction motor, when major consideration is

A

Slop speed operation

B

High starting torque

C

Low windage losses

D

All of the above

A thin mild steel wire is loaded by adding loads in equal increments till it breaks. The extensions noted with increasing loads will behave as under

A

Uniform throughout

B

Increase uniformly

C

First increase and then decrease

D

Increase uniformly first and then increase rapidly

While starting a synchronous motor by induction motor action, field winding is usually

A

connected to D.C. supply

B

short-circuited by low resistance

C

kept open-circuited

D

none of the above

A synchronous motor has better power factor as compared to that of an equivalent induction motor. This is mainly because

A

synchronous motor has no slip

B

stator supply is not required to produce magnetic field

C

mechanical load on the rotor remains constant

D

synchronous motor has large airgap

While starting a salient pole synchronous motor by induction motor action and connecting field discharge resistance across field, starting and accelerting torque is produced by

A

induction motor torque in field winding

B

induction motor torque in damper winding

C

eddy current and hysteresis torque in pole faces

D

reHetance motor torque due to saliency of the rotor

E

all of the above methods

Slip ring motor is preferred over squirrel cage induction motor where

A

High starting torque is required

B

Load torque is heavy

C

Heavy pull out torque is required

D

All of the above

The power factor of a synchronous motor is better than that of induction motor because

A

stator supply is relieved of responsibility of producing magnetic field

B

mechanical load on the motor can be adjusted

C

synchronous motor runs at synchronous speed

D

synchronous motor has large air gap

An important advantage of a synchronous motor over wound round induction motor is that

A

its power factor may be varied at will

B

its speed is independent of supply frequency

C

its speed may be controlled more easily

D

none of the above

Mass moment of inertia of a thin rod about its one end is ___________ the mass moment of inertia of the same rod about its mid-point

A

Same as

B

Twice

C

Thrice

D

Four times

The ratio of the moment of inertia of a rectangle about its centroidal axis to the moment of inertia about its base, is

A

$$\frac{1}{4}$$

B

$$\frac{1}{2}$$

C

$$\frac{3}{4}$$

D

$$2$$

For driving high inertia loads best type of induction motor suggested is

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