A series generator can self-excite

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

A separately excited generator as compared to a self-excited generator

A

Is amenable to better voltage control

B

Is more stable

C

Has exciting current independent of load current

D

Has all above features

Which of the following components of a D.C, generator plays vital role for providing direct current of a D.C. generator?

A

Dummy coils

B

Commutator

C

Eye bolt

D

Equalizer rings

The losses occurring in a D.C. generator are given below. Which loss is likely to have highest proportion at rated load of the generator?

A

Hysteresis loss

B

Field copper loss

C

Armature copper loss

D

Eddy current loss

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

D.C. series generator is used

A

To supply traction load

B

To supply industrial load at constant voltage

C

Voltage at the toad end of the feeder

D

For none of the above purpose

A capacitor and a resistor are connected in series to a sine wave generator. The frequency is set so that the capacitive reactance is equal to the resistance and, thus, an equal amount of voltage appears across each component. If the frequency is increased

A

VR > VC

B

VC > VR

C

VR = VC

D

VR and VC = 0

In a D.C. generator the critical resistance can be increased by

A

Increasing its field resistance

B

Decreasing its field resistance

C

Increasing its speed

D

Decreasing its 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

A D.C. generator can be considered as

A

Rectifier

B

Prime mover

C

Rotating amplifier

D

Power pump

A series generator can self-excite

Related Questions