Question 1

The voltage transformation ratio of a transformer is equal to the ratio of

Accepted Answer

A) primary turns to secondary turns 
B) secondary current to primary current 
C) secondary induced e.m.f. to primary induced e.m.f. 
D) secondary terminal voltage to primary applied voltage 
A) primary turns to secondary turns 
B) secondary current to primary current 
C) secondary induced e.m.f. to primary induced e.m.f. 
D) secondary terminal voltage to primary applied voltage

Question 2

If a transformer is switched on to a voltage more than the rated voltage

Accepted Answer

A) its power factor will deteriorate 
B) its power factor will increase 
C) its power factor will remain unaffected 
D) its power factor will be zero 
A) its power factor will deteriorate 
B) its power factor will increase 
C) its power factor will remain unaffected 
D) its power factor will be zero

Question 3

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 4

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 5

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

The voltage transformation ratio of a transformer is equal to the ratio of

If a transformer is switched on to a voltage more than the rated voltage

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

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

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

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

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Exam 6: Transformer and D.C Motor

The voltage transformation ratio of a transformer is equal to the ratio of

If a transformer is switched on to a voltage more than the rated voltage

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

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

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

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