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Question

Answer 1

5.3)

The purpose of capacitor in a single phase capacitor motor:

Single phase induction motor is not the self starting so, to make it self start we can use capacitor.

Capacitor also provides high starting torque to run the motor.

The capacitor is used to make a single-phase motor rotate in one direction only by supplying a phase shift voltage to a starting winding on the motor.

Answer 2

5.4)

Transformer needs a cooling system. Transformers can be divided in two types as (i) dry type transformers and (ii) oil immersed transformers.

Different cooling methods of transformer are -

For dry type transformers:

Natural air cooling

Blast air cooling

For oil immersed transformers:

1) ONAN - Oil Natural Air Natural

2) ONAF - Oil Natural Air Forced

3) OFAF - Oil Forced Air Forced

4) OFWF - Oil Forced Air Forced.

Answer 3

5.5)

Feeder is defined as lines, which connect the distribution station and distributor.

Distributor is defined as a common bus bar, which connect the service main and feeder.

The most two types of feeders used in transmission system are,

1) Radial distribution system.

2) Primary Loop distribution system.

Answer 4

5.2)

There are different types of capacitors.

Few examples of capacitors:

Dielectric Capacitor

Film Capacitor

Ceramic Capacitor

Electrolytic Capacitor.

Answer 5

Step 1:

(5.1)

A single phase transformer has a primary turns.

Transformer has a secondary turns.

Secondary voltage is V.

(5.1.1)

Find the primary voltage.

Relation between number of turns and voltage is .

Substitute , and .

The primary voltage 400 V.

Solution :

The primary voltage 400 V.

Answer 6

Step 1:

(5.1.2)

A single phase transformer has a primary turns.

Transformer has a secondary turns.

Secondary current is A.

Find the primary current.

Relation between number of turns and voltage is .

Substitute , and .

The primary current 10 A.

Solution :

The primary current 10 A.

Answer 7

Step 1:

(5.1.3)

The primary current 10 A.         [From 5.1.2]

The primary voltage 400 V.       [From 5.1.1]

Power factor of primary current is .

Primary power of the transformer is  .

The primary power 2400 W.

Solution :

The primary power of transformer 2400 W.