A cumulatively compounded long shunt generator when operating as a motor would be

The e.m.f. generated by a shunt wound D.C. generator is E. Now while pole flux remains constant, if the speed of the generator is doubled, the e.m.f. generated will be

A

$$\frac{{\text{E}}}{2}$$

B

2E

C

Slightly less than E

D

E

If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens

A

This will make armature to take heavy current, possibly burning it

B

This will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses

C

Nothing will happen to motor

D

Motor will come to stop

If a D.C. shunt motor is working at no load and if shunt field circuit suddenly opens

A

Nothing will happen to the motor

B

This will make armature to take heavy current, possibly burning it

C

This will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses

D

Motor will run at very slow speed

In a differentially compounded D.C. motor, if shunt field suddenly opens

A

The motor will first stop and then run in opposite direction as series motor

B

The motor will work as series motor and run at slow speed in the same direction

C

The motor will work as series motor and run at high speed in the same direction

D

The motor will not work and come to stop

If the speed of a D.C. shunt motor is increased, the back e.m.f. of the motor will

A

Increase

B

Decrease

C

Remain same

D

Become zero

If the field of a D.C. shunt motor gets opened while motor is running

A

The speed of motor will be reduced %

B

The armature current will reduce

C

The motor will attain dangerously high speed 1

D

The motor will continue to run at constant speed

A shunt generator can self-excite

A

Only if the resistance of the field circuit is less than critical value

B

Only if the resistance of the field circuit is greater than critical value

C

Irrespective of the value of the resistance in the field circuit

D

None of the above

In a shunt generator the voltage build up is generally restricted by

A

speed limitation

B

armature heating

C

insulation restrictions

D

saturation of iron

The series field of a short-shunt D.C. generator is excited by

A

external current

B

armature current

C

shunt current

D

load current

The terminal voltage of a D.C. shunt generator drops on load because of all of the following reasons except

A

Armature reaction

B

Armature resistance drop

C

Field weakening due to armature reaction and armature

D

Commutation

A cumulatively compounded long shunt generator when operating as a motor would be

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