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Electrical Machines-I 4th Sem EEE May 2016 PSBTE Paper

Electrical Machines-I 4th Sem EEE May 2016 PSBTE Paper                                                              SECTION-A

Q1. Fill in the Blanks                                                                                                   15×1=15

1. The magnitude of induced emf is directly proportional to rate of change of Flux
2. Under____ condition magnets do not move away from each Other.
3. Direction of torque depends upon Axis Of Rotation of torque angle.
4. DC series motor is used for vacuum cleaner, traction systems, sewing machines, cranes
5. Interpoles are used for  Reduces the effect of Armature Reaction in DC Machine.
6. DC motor starter is used for Heavily starting current.
7. Transformer is a Static machine
8. Transformer core is made of silicon steel to reduce Eddy Current Losses.
9. Condition for maximum efficiency is copper losses is equal to Iron Losses.
10. Transformer steps up or steps down voltage .

SECTION-B

Q2. Attempt any five questions.                                                 5×6=30

1. What are advantages of three phase transformer over single phase transformer?
2. Explain working of auto Transformer ?
3. What is transformer? Explain its construction and working.
4. Explain various losses in d.c Generator ?
5. Name the main parts of c machine and explain their functions.
6. Compare features of generator and Motor ?

SECTION-C

Q3. Attempt any three questions.                                                          3×10=30

1. Explain constructions of three phase Transfomer ?
2. What are instrument transformers? Explain PT working Principle ?
3. Explain various methods of speed control of c shunt motor. Explain any one.
4. Explain concept of torque production in an electrical machine.

Section a:-ELECTRICAL MACHINES-I 4th/2520/0952/ELECT/EEE/May 2016

The magnitude of induced emf is directly proportional to rate of change of Flux

Under ___ condition magnets do not move away from each Other.

Direction of torque depends upon Axis Of Rotation of torque angle.

DC series motor is used for vacuum cleaner, traction systems, sewing machines, cranes

Interpoles are used for  Reduces the effect of Armature Reaction in DC Machine.

DC motor starter is used for Heavily starting current.

Transformer is a Static machine

Transformer core is made of silicon steel to reduce Eddy Current Losses.

Condition for maximum efficiency is copper losses is equal to Iron Losses.

Transformer steps up or steps down voltage

Section B :ELECTRICAL MACHINES-I 4th/2520/0952/ELECT/EEE/May 2016

Advantages of three phase transformer over single phase transformer

Working of auto Transformer

What is transformer and its construction and working

Various losses in d.c Generator

Name the main parts of c machine

Comparison the features of generator and Motor

ELECTRICAL MACHINES-I 4th/2520/0952/ELECT/EEE/May 2016

Section c ELECTRICAL MACHINES-I 4th/2520/0952/ELECT/EEE/May 2016

Constructions of three phase Transfomer

instrument transformers

Explain PT working Principle

Methods of speed control of dc shunt motor

Concept of torque production in an electrical machine