The torque produced in induction type relay (shaded pole structure) is

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 small square region inside a larger square is shaded. The diagonal of the larger square is three times the diagonal of the small square in length. What fraction of the area of the larger square is not shaded?

A

1/9

B

1/3

C

2/3

D

8/9

Radius of circle center 0 is 3 times the radius of circle center C. Angle ACB -A angle POQ. If the shaded are of circle C is 2 then what is the area of then shaded part of circleO?

A

36

B

9

C

12

D

18

In a shaded pole single-phase motor, the revolving field is produced by the use of

A

inductor

B

capacitor

C

resistor

D

shading coils

Admittance relay is _______ relay.

A

impedance

B

directional

C

non-directional

D

none of the above

There are 23 poles with a constant distance between each pole. A car takes 24 seconds to reach the 12th pole. How much more time will it take to reach the last pole?

A

40 seconds

B

44 seconds

C

48 seconds

D

46 seconds

A shaded pole motor does not possess

A

centrifugal switch

B

capacitor

C

commutator

D

all of the above

The range of efficiency for shaded pole motors is

A

95% to 99%

B

80% to 90%

C

50% to 75%

D

5% to 35%

In a shaded pole motor, the shading coil usually consist of

A

a single turn of heavy wire which is in parallel with running winding

B

a single turn of heavy copper wire which is short-circuited and carries only induced current

C

a multilayer fine gauge copper wire in parallel with running winding

D

none of the above

The shaded pole motor is used for

A

high starting torque

B

low starting torque

C

medium starting torque

D

very high starting torque

The torque produced in induction type relay (shaded pole structure) is

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