Electric Machines Quiz

What was once the most popular type of machine due to its ability to control speed and direction?

• AC machines

• DC machines

• Hydraulic machines

• Pneumatic machines

Why did the use of DC machines decrease in the past?

• They were too expensive

• They were less efficient

• Cheaper AC alternatives became available

• They were too complex to operate

What must a competent electrician have knowledge of according to the text?

• AC machine operating principles

• DC machine operating principles

• Both AC and DC machine operating principles

• Only modern machine operating principles

What are the three basic features of DC machines?

• Magnetic-field system, system of conductors, provision for relative movement

• Magnetic-field system, system of insulators, provision for absolute movement

• Electric-field system, system of conductors, provision for relative movement

• Electric-field system, system of insulators, provision for absolute movement

What is the stationary part of a DC machine called?

• Rotor

• Armature

• Commutator

• Field windings

What is the rotating part of a DC machine known as?

• Rotor

• Armature

• Commutator

• Field windings

How is power delivered to or taken from the armature in a DC machine?

• Through the rotor

• Through the stator

• By brushes in contact with the moving commutator

• By direct contact with the field windings

What type of energy is supplied to a DC generator?

• Electrical energy

• Mechanical energy

• Thermal energy

• Chemical energy

What is the main function of the commutator in a DC generator?

• To increase the voltage

• To decrease the current

• To reverse the current flow

• To store electrical energy

What component in a DC generator ensures that the current in both conductors will always be the same?

• Armature

• Brushes

• Commutator

• Loops