DC Generators

Problem 477: A four-pole, DC generator with lap winding has 48 slots and 4 elements per slot. How many coils does it have?

Problem 478: If the armature of an eight-pole machine were wound with a simplex wave winding, how many parallel paths would there be?

Problem 490: The field current of a 100 kW, 250-volt shunt generator is 5 amperes when delivering power at rated terminal voltage and rated load current. The combined armature and brush resistance is 0.01 ohm. Determine the efficiency of the generator.

Problem 524: Two shunt generators are operating in parallel and taking equal shares of a 2400 A, 230 V bus load. Ratings: Generator 1 (3% reg, 500 kW, 250V), Generator 2 (4% reg, 600 kW, 250V). If an additional 600-A load is connected to the bus, determine the current delivered by each generator at this condition.

What is the nature of the current flowing in the armature of DC machine?

In a 4 pole, 35 slot, dc armature, 180 electrical degrees coil span will be obtained when coils occupy _ slots.

An 8 pole lap wound dc generator has 1000 conductors in its armature. The flux produced per pole is 20 mWb and emf generated is 400 v. What is the speed of the machine?

The number of parallel paths in a simplex lap winding is equal to

If the resistance of the field winding of a dc generator is increased the output voltage will

Brushes of dc machine are usually made of

A dc shunt generator has an induced voltage of 220 V on open circuit. When the machine is on load the voltage is 200 V. Find the load current if the field resistance is 100 Ω and the armature resistance is 0.2 Ω.

A device that repeatedly reverse the polarity of a magnetic field in order to keep a dc motor rotating is known as

The dc generator used as pilot exciter is

An 8-pole lap wound dc generator has 1,000 armature conductors, flux of 20 mWb per pole and emf generated is 400 v. What is the speed of the machine?

In DC machines, lap winding is used for

A dc machine has 8 poles and a rated current of 100A. How much current will flow in each conductor at rated condition if the armature is simplex lap wound?

Shunt generators are used where the main requirement is constant

A 4-pole lap-wound armature has 480 conductors and a flux per pole of 25mWb. What is the emf generated, when running at 600 rpm?

What is the nature of the current flowing in the armature of dc machine?

The current flowing in the armature conductors of a dc motor is