SIM- Module 1

Majority of alternators in use have ..............................................................................................

• revolving ac armature winding

• stationary field type construction

• revolving field type construction

• none of the above

The field winding of alternator is ..................................................... excited.

• d.c or a.c

• a.c

• d.c

• none of these

The ac armature winding of alternator operates at .................................................the field winding.

• the same voltage as

• much lesser voltage than

• much higher voltage than

• none of these

An alternator is also called as ............................................... generator.

• induction

• synchronous

• asynchronous

• semi-synchronous

The nonsalient pole field construction is used for .......................................................alternator.

• low speed

• medium speed

• high speed

• very slow speed

The low speed alternators are generally driven by ..................................................................... .

• hydraulic turbines

• steam turbine

• steam engine

• gas turbine

Alternator operates on the principle of ......................................................

• self induction

• mutual induction

• self or mutual induction

• electromagnetic induction

Which type of alternators are used in hydro electric power station ?

• Steam turbine alternator

• Turbo alternator

• Salient pole alternator

• Cylindrical pole alternator

Alternators are usually designated to generate which type of AC voltage?

• with fixed frequency

• with variable frequency

• fixed current

• fixed power factor

State whether the following statements are true or FALSE.

1. Salient pole rotor alternators have non-uniform airgap.

2. Salient pole rotor alternators are mechanically robust.

• 1 is true but 2 is false.

• 1 is false but 2 is true

• Both 1 and 2 are false

• Both 1 and 2 are true