Alternators

Problem 571: What is the speed of a 100 kW, 230-volt, three-phase, four-pole, 60 Hz alternator?

Problem 572: A six-pole, 3-phase AC generator has 72 slots, the coil span is 12. What is the pitch factor?

Problem 578: A three-phase, 6-pole, 72-slot armature of a synchronous generator is wound using a two-layer lap coil having 20 conductors per coil with a pitch of 83.33%. The flux per pole is 4,800,000 maxwells. If the rotor of the generator is driven at a speed of 1200 rpm, calculate the induced emf per phase.

With reduction of load on alternator

An alternator running in parallel with the other alternators all having automatic voltage regulators is to be taken off the bus. The usual procedure before opening the switch is to

Slip rings are made of

Calculate the average voltage generated in a six turn full pitch coil of a 60 cycle alternator if the flux per pole is \(7.2 \times 10^{5}\) maxwells.

As load pf of an alternator becomes more leading, the value of the generated voltage required to give rated terminal voltage _.

For a coil having a span of 2/3 of pole pitch, the coil span factor is

If the input of the prime mover of an alternator is kept constant but the excitation is increased then

The power factor of an alternator is determined by its

One advantage of distributing the winding in alternator is to

One advantage of distributing the winding in alternator is to

One of the advantages of distributing the winding in alternator is to

If the input of the prime mover of an alternator is kept constant but excitation is increased, then

A winding is short pitched by 60 degrees electrical. Its pitch factor is:

In a 10-pole synchronous machine, 20 electrical degrees are equivalent to how many mechanical degrees?

Calculate the average voltage generated in a six-turn full-pitch coil of a 25-cycle alternator if the flux per pole is \(7.2 \times 10^{5}\) maxwells.

For proper parallel operation, ac polyphase alternators must have the same ______

A 500 kVA alternator operates at 80% of full load with an efficiency of 92 percent. If the load power factor is 0.8, calculate the total loss.