The speed of a D.C. shunt motor more than its full-load speed can be obtained by

In an actual transformer the iron loss remains practically constant from noload to fullload because

A

value of transformation ratio remains constant

B

permeability of transformer core remains constant

C

core flux remains practically constant

D

primary voltage remains constant

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

The speed of a DC shunt motor is required to be more than full load speed . This is possible by-

A

reducing the field current

B

decreasing the armature current

C

increasing the armature current

D

None of the above

The speed of a D.C. shunt motor is required to be more than full load speed. This is possible by

A

Reducing the field current

B

Decreasing the armature current

C

Increasing the armature current

D

Increasing the excitation current

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

L is older than M and taller than N. O is younger than P, older than N and shorter than Q. R is older than S, younger than N, shorter than S and taller than Q. S is older than L, M, O, P, Q, R and S is necessarily false?

A

O is the shortest of the group.

B

N is the second tallest of the group.

C

L is the tallest of the group.

D

Q is the third oldest of the group.

There are five statements given below: i. karim earns more than Rahim but less than Raihan ii. Tarique earns more than Farid iii. Rahim earns more than Rariq iv. Raihan and Rarique earn equal amounts v. Farid earns the least amount which of the above statements prove that Tarique earns more money than Rafiq?

A

I, II and III

B

II, III and IV

C

III, IV and V

D

I, III and IV

The speed of a D.C. shunt motor can be increased by

A

Increasing the resistance in armature circuit

B

Increasing the resistance in field circuit

C

Reducing the resistance in the field circuit

D

Reducing the resistance in the armature circuit

The speed of a D.C. shunt motor more than its full-load speed can be obtained by

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