Motors 1

In DC generator, what converts the AC emf to DC

The commutator

The field poles are made of iron , either solid or laminations and support coils of wire called

Field windings

AC generators are also called _________, since they produce an alternating current .

Alternators

A single hertz cycle will result if the loop makes one revolution each ______ . A complete cycle is 360 degrees

A second

In electrical machines , the type of voltage generated at the armature winding is

AC

Commutators are found on

DC motors

A _________ is an electric machine used to convert mechanical energy into electrical energy , and is called a generator or alternator.

Dynamo

The two essential parts of rotating generators are the

Electromagnets or permanent magnets and armature winding

The alternator must be driven at a definite constant speed to keep the _________ constant

Frequency

Electrical machines that convert mechanical energy to electrical energy are

Generators

It would not be an exaggeration to say that all of the electricity used in the industry is based on the generation and utilization of

Magnetic fields

Electrical machines that convert electrical energy to mechanical energy are

Motors

Generation of voltage in a generator happens when there is a

Relative motion between conducting wires and magnetic lines of force

The ________ AC generator is by far the most widely used today. In this type of generator , direct current from a separate source ( excitation ) is passed through field windings on the rotor by means of slip rings and brushes .

Revolving field

There are two alternations in one complete cycle. One positive and one negative alternation . This is called _______

Sine wave

The _________ of all alternators are basically the same and consist of a laminated , slotted , good magnetic steel core and an armature winding placed in the slots like it is in a DC generator

Stator

There must be a motion between the armature windings and the field windings . AC generators are built in two major assemblies, the ________ and the rotor.

Stator

The meaning of this term lines of force is used to designate the _______ of the magnet .

Strength

For a single loop rotating in a two pole field one North Pole and one South Pole , you can see that each time the loop makes one complete revolution the current reverses direction

Twice