Question 1

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 constantspeed 
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 constantspeed C

Question 2

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 D

Question 3

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

Question 4

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. whilestarting 
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. whilestarting

Question 5

A no-load test is performed on a transformer to determine

Accepted Answer

A) core loss 
B) copper loss 
C) efficiency 
D) magnetising current and loss 
A) core loss 
B) copper loss 
C) efficiency 
D) magnetising current and loss

Question 6

A D.C. series motor is that which

Accepted Answer

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

Question 7

In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of

Accepted Answer

A) less than 15 A 
B) more than 15 A 
C) 15 A 
D) none of the above 
A) less than 15 A 
B) more than 15 A 
C) 15 A 
D) none of the above

Question 8

Minimum voltage regulation occurs when the power factor of the load is

Accepted Answer

A) unity 
B) lagging 
C) leading 
D) zero 
A) unity 
B) lagging 
C) leading 
D) zero

Question 9

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 10

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 11

Auto-transformer makes effective saving on copper and copper losses, whenits transformation ratio is

Accepted Answer

A) approximately equal to one 
B) less than one 
C) great than one 
D) none of the above 
A) approximately equal to one 
B) less than one 
C) great than one 
D) none of the above

Question 12

An open-circuit test on a transformer is conducted primarily to measure

Accepted Answer

A) insulation resistance 
B) copper loss 
C) core loss 
D) total loss 
A) insulation resistance 
B) copper loss 
C) core loss 
D) total loss

Question 13

Part of the transformer which is most subject to damage from overheating is

Accepted Answer

A) iron core 
B) copper winding 
C) winding insulation 
D) frame or case 
A) iron core 
B) copper winding 
C) winding insulation 
D) frame or case

Question 14

In D.C. shunt motors as load is reduced

Accepted Answer

A) the speed will increase abruptly 
B) the speed will increase in proportion to reduction in load 
C) the speed will remain almost/constant 
D) the speed will reduce 
A) the speed will increase abruptly 
B) the speed will increase in proportion to reduction in load 
C) the speed will remain almost/constant 
D) the speed will reduce

Question 15

Differentially compound D.C. motors can find applicationsrequiring

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 16

If a D.C. motor is connected across the A.C. supply it will

Accepted Answer

A) run at normal speed 
B) not run 
C) run at lower speed 
D) burn due to heat produced in the field winding by .eddy currents 
A) run at normal speed 
B) not run 
C) run at lower speed 
D) burn due to heat produced in the field winding by .eddy currents

Question 17

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 18

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

Question 19

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

Question 20

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

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

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

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

Starters are used with D.C. motors because

A no-load test is performed on a transformer to determine

A D.C. series motor is that which

In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of

Minimum voltage regulation occurs when the power factor of the load is

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

Which D.C. motor is preferred for elevators ?

Auto-transformer makes effective saving on copper and copper losses, whenits transformation ratio is

An open-circuit test on a transformer is conducted primarily to measure

Part of the transformer which is most subject to damage from overheating is

In D.C. shunt motors as load is reduced

Differentially compound D.C. motors can find applicationsrequiring

If a D.C. motor is connected across the A.C. supply it will

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

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

Which of the following application requires high starting torque ?

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

Transformer Fundamentals and Operation

Transformer Technology and Design

Transformer: Resistance, Oil, Relays, Harmonics, and Core Properties

Transformers: Efficiency, Design, and Testing

Transformers: Voltage Regulation, Efficiency, and Protection

D.C Motors and Starters

D.C Motors and Speed Control

D.C Motors and Controls

D.C Motors and Generators

D.C Machine and Generator Laminations, Commutation, and Components

D.C Generators and Commutators

D.C Generator Operation and Construction

D.C Generators

Direct Current Generators and Parallel Operation

Filters

Exam 6: Transformer and D.C Motor

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

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

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

Starters are used with D.C. motors because

A no-load test is performed on a transformer to determine

A D.C. series motor is that which

In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of

Minimum voltage regulation occurs when the power factor of the load is

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

Which D.C. motor is preferred for elevators ?

Auto-transformer makes effective saving on copper and copper losses, whenits transformation ratio is

An open-circuit test on a transformer is conducted primarily to measure

Part of the transformer which is most subject to damage from overheating is

In D.C. shunt motors as load is reduced

Differentially compound D.C. motors can find applicationsrequiring

If a D.C. motor is connected across the A.C. supply it will

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

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

Which of the following application requires high starting torque ?

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

Transformer Fundamentals and Operation

Transformer Technology and Design

Transformer: Resistance, Oil, Relays, Harmonics, and Core Properties

Transformers: Efficiency, Design, and Testing

Transformers: Voltage Regulation, Efficiency, and Protection

D.C Motors and Starters

D.C Motors and Speed Control

D.C Motors and Controls

D.C Motors and Generators

D.C Machine and Generator Laminations, Commutation, and Components

D.C Generators and Commutators

D.C Generator Operation and Construction

D.C Generators

Direct Current Generators and Parallel Operation

Filters