If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will

If the field circuit of an unloaded salientpole synchronous motor gets suddenly open-circuited, then

A

it runs at a slower speed

B

the motor stops

C

it continues to run at the same speed

D

it runs at a very high speed

When the excitation of an unloaded salient pole synchronous motor suddenly gets disconnected

A

the motor stops

B

it runs as a reluctance motor at the same speed

C

it runs as a reluctance motor at a lower speed

D

none of the above

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

A synchronous motor installed at the receiving end substation operates with such an excitation that it takes power at lagging power factor. Now if the applied voltage of the synchronous motor goes down, the power factor of the synchronous motor will

A

remain same

B

go down

C

improve

D

none of the above

In case one phase of a three-phase synchronous motor is short-circuited the motor will

A

Not start

B

Run at $$\frac{2}{3}$$ of synchronous speed

C

Run with excessive vibrations

D

Take less than the rated load

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

What are the salient features of the new scheme? Choose the meaning of salient.

A

silent

B

main

C

minor

D

stable

The length of a rectangular field F is 3 km greater than the side of a square field M , and the width of field F is 3 km less then the side of field M. If the area of field M is m2 square km, what is the area of field F?

A

m2 +6

B

6

C

m2 - 6

D

m2 +9

The mixing vat in a factory receives liquid ingredients through six separate value--- labeled R.S.T.U,Y and Z -- each of which has exactly two settings: open and closed.The mixing vat operator must ensure that each valve is set open or closed according to the following conditions: If T is open, both S and Z must be closed, R and Z cannot both be closed at the same time; If Y is closed, Z must also be closed;S and U cannot both be open at the same time. If Z is open, which of the following must be true?

A

S is open

B

T is open

C

U is open

D

y is open

The mixing vat in a factory receives liquid ingredients through six separate value--- labeled R.S.T.U,Y and Z -- each of which has exactly two settings: open and closed.The mixing vat operator must ensure that each valve is set open or closed according to the following conditions: If T is open, both S and Z must be closed, R and Z cannot both be closed at the same time; If Y is closed, Z must also be closed;S and U cannot both be open at the same time. If R is closed and U is open, which of the following must be true?

A

S is open

B

T is open

C

T is closed

D

Y is closed

If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will

Related Questions