Question 1

The direction of rotation of a D.C. series motor can be changed by

Accepted Answer

A) interchanging supply terminals 
B) interchanging field terminals 
C) either of (a) and (b) above 
D) None of the above 
A) interchanging supply terminals 
B) interchanging field terminals 
C) either of (a) and (b) above 
D) None of the above B

Question 2

In a D.C. shunt motor, speed is

Accepted Answer

A) independent of armature current 
B) directly proportional to the armature current 
C) proportional to the square of the current 
D) inversely proportional to the armature current 
A) independent of armature current 
B) directly proportional to the armature current 
C) proportional to the square of the current 
D) inversely proportional to the armature current A

Question 3

Which of the following application requires high starting torque ?

Accepted Answer

A) Lathe machine 
B) Centrifugal pump 
C) Locomotive 
D) Air blower 
A) Lathe machine 
B) Centrifugal pump 
C) Locomotive 
D) Air blower C

Question 4

To get the speed of D.C, motor below the normal without wastage of electrical energy is used.

Accepted Answer

A) Ward Leonard control 
B) rheostatic control 
C) any of the above method 
D) none of the above method 
A) Ward Leonard control 
B) rheostatic control 
C) any of the above method 
D) none of the above method

Question 5

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

Accepted Answer

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 nuvat constant speed 
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 nuvat constant speed

Question 6

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

Accepted Answer

A) decreasing the field current 
B) increasing the field current 
C) decreasing the armature current 
D) increasing the armature current 
A) decreasing the field current 
B) increasing the field current 
C) decreasing the armature current 
D) increasing the armature current

Question 7

If a D.C. motor is to be selected for conveyors, which rriotor would be preferred ?

Accepted Answer

A) Series motor 
B) Shunt motor 
C) Differentially compound motor 
D) Cumulative compound motor 
A) Series motor 
B) Shunt motor 
C) Differentially compound motor 
D) Cumulative compound motor

Question 8

These days D.C. motors are widely used in

Accepted Answer

A) pumping sets 
B) air compressors 
C) electric traction 
D) machine shops 
A) pumping sets 
B) air compressors 
C) electric traction 
D) machine shops

Question 9

Which D.C. motor will be preferred for machine tools ?

Accepted Answer

A) Series motor 
B) Shunt motor 
C) Cumulative compound motor 
D) Differential compound motor 
A) Series motor 
B) Shunt motor 
C) Cumulative compound motor 
D) Differential compound motor

Question 10

When two D.C. series motors are connected in parallel, the resultant speed is

Accepted Answer

A) more than the normal speed 
B) loss than the normal speed 
C) normal speed 
D) zero 
A) more than the normal speed 
B) loss than the normal speed 
C) normal speed 
D) zero

Question 11

In case of D.C. shunt motors the speed is dependent on back e.m.f. only because

Accepted Answer

A) back e.m.f. is equal to armature drop 
B) armature drop is negligible 
C) flux is proportional to armature current 
D) flux is practically constant in D:C. shunt motors 
A) back e.m.f. is equal to armature drop 
B) armature drop is negligible 
C) flux is proportional to armature current 
D) flux is practically constant in D:C. shunt motors

Question 12

What will happen if the back e.m.f. of a D.C. motor vanishes suddenly?

Accepted Answer

A) The motor will stop 
B) The motor will continue to run 
C) The armature may burn 
D) The motor will run noisy 
A) The motor will stop 
B) The motor will continue to run 
C) The armature may burn 
D) The motor will run noisy

Question 13

Starters are used with D.C. motors because

Accepted Answer

A) these motors have high starting torque 
B) these motors are not self-starting 
C) back e.m.f. of these motors is zero initially 
D) to restrict armature current as there is no back e.m.f. while starting 
A) these motors have high starting torque 
B) these motors are not self-starting 
C) back e.m.f. of these motors is zero initially 
D) to restrict armature current as there is no back e.m.f. while starting

Question 14

No-load speed of which of the following motor will be highest ?

Accepted Answer

A) Shunt motor 
B) Series motor 
C) Cumulative compound motor 
D) Differentiate compound motor 
A) Shunt motor 
B) Series motor 
C) Cumulative compound motor 
D) Differentiate compound motor

Question 15

For starting a D.C. motor a starter is required because

Accepted Answer

A) it limits the speed of the motor 
B) it limits the starting current to a safe value 
C) it starts the motor 
D) none of the above 
A) it limits the speed of the motor 
B) it limits the starting current to a safe value 
C) it starts the motor 
D) none of the above

Question 16

According to Fleming's left-hand rule, when the forefinger points in the direction of the field or flux, the middle finger will point in the direction of

Accepted Answer

A) current in the conductor aovtaat of conductor 
B) resultant force on conductor 
C) none of the above 
A) current in the conductor aovtaat of conductor 
B) resultant force on conductor 
C) none of the above

Question 17

Differentially compound D.C. motors can find applications requiring

Accepted Answer

A) high starting torque 
B) low starting torque 
C) variable speed 
D) frequent on-off cycles 
A) high starting torque 
B) low starting torque 
C) variable speed 
D) frequent on-off cycles

Question 18

Which D.C. motor is preferred for elevators ?

Accepted Answer

A) Shunt motor 
B) Series motor 
C) Differential compound motor 
D) Cumulative compound motor 
A) Shunt motor 
B) Series motor 
C) Differential compound motor 
D) Cumulative compound motor

Question 19

The type of D.C. motor used for shears and punches is

Accepted Answer

A) shunt motor 
B) series motor 
C) differential compoutid D.C. motor 
D) cumulative compound D.C. motor 
A) shunt motor 
B) series motor 
C) differential compoutid D.C. motor 
D) cumulative compound D.C. motor

Question 20

A D.C. series motor is that which

Accepted Answer

A) has its field winding consisting of thick wire and less turns 
B) has a poor torque 
C) can be started easily without load 
D) has almost constant speed 
A) has its field winding consisting of thick wire and less turns 
B) has a poor torque 
C) can be started easily without load 
D) has almost constant speed

The direction of rotation of a D.C. series motor can be changed by

In a D.C. shunt motor, speed is

Which of the following application requires high starting torque ?

To get the speed of D.C, motor below the normal without wastage of electrical energy is used.

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

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

If a D.C. motor is to be selected for conveyors, which rriotor would be preferred ?

These days D.C. motors are widely used in

Which D.C. motor will be preferred for machine tools ?

When two D.C. series motors are connected in parallel, the resultant speed is

In case of D.C. shunt motors the speed is dependent on back e.m.f. only because

What will happen if the back e.m.f. of a D.C. motor vanishes suddenly?

Starters are used with D.C. motors because

No-load speed of which of the following motor will be highest ?

For starting a D.C. motor a starter is required because

According to Fleming's left-hand rule, when the forefinger points in the direction of the field or flux, the middle finger will point in the direction of

Differentially compound D.C. motors can find applications requiring

Which D.C. motor is preferred for elevators ?

The type of D.C. motor used for shears and punches is

A D.C. series motor is that which

D.C. Motors

D.C. Motors and Speed Control

D.C. Motors and Generators

D.C. Generator and Motor Efficiency, Testing and Braking Techniques

Filters

Exam 1: D.C. Motors and Their Applications

The direction of rotation of a D.C. series motor can be changed by

In a D.C. shunt motor, speed is

Which of the following application requires high starting torque ?

To get the speed of D.C, motor below the normal without wastage of electrical energy is used.

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

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

If a D.C. motor is to be selected for conveyors, which rriotor would be preferred ?

These days D.C. motors are widely used in

Which D.C. motor will be preferred for machine tools ?

When two D.C. series motors are connected in parallel, the resultant speed is

In case of D.C. shunt motors the speed is dependent on back e.m.f. only because

What will happen if the back e.m.f. of a D.C. motor vanishes suddenly?

Starters are used with D.C. motors because

No-load speed of which of the following motor will be highest ?

For starting a D.C. motor a starter is required because

According to Fleming's left-hand rule, when the forefinger points in the direction of the field or flux, the middle finger will point in the direction of

Differentially compound D.C. motors can find applications requiring

Which D.C. motor is preferred for elevators ?

The type of D.C. motor used for shears and punches is

A D.C. series motor is that which

D.C. Motors

D.C. Motors and Speed Control

D.C. Motors and Generators

D.C. Generator and Motor Efficiency, Testing and Braking Techniques

Filters