DC machines

Question 1

what is the formula for DC machines

Answer 1

F = BIL (Newtons)

Question 2

What is the principle of operation of all motors

Answer 2

Flemings left-hand law

Question 3

Generally, what are the two windings

Answer 3

• Aemeture winding
• Feild winding

Question 4

What is the rotating part of the machine called

Answer 4

Armeture

Question 5

What is the part that is mounted on the armeture

Answer 5

Brushes

Question 6

What is it called that surrounds the machine

Answer 6

Frame or Yoke

Question 7

What are the three main motors

Answer 7

• Series-wound motor
• Shunt- (or parellel-) motor
• Compound-wound motor

Question 8

How does a Series-wound mototr work

Answer 8

Beacuase the series and armature windings are connected in series, more current is drawn, increaseing strength of the magnetic field winding, generating torque

Question 9

How does a parellel- (shunt-) wound motor work

Answer 9

Because the field windings are connected in parellel across supply, It always draw the same current irrestpective to the currnet drawn by the armature

Question 10

How does a Copmound-wound motor

Answer 10

• Its connected to series and in parellel (shunt), a motor connects with the armature and field windings in a shunt and a series combination.
• This motor is used when both a high starting torque and food speed regulation are needed