Deck 15: Summary Review of

Question 1

The accompanying picture shows a standard double-loop armature and its corresponding torque graph for one complete revolution. Would the graph look the same if one of the two loops was rotated 90º so that the two loops were parallel to one another? If so, why? If not, draw or describe the new graph.

Answer 1

If you were to rotate one of the two conductors 90º, the torque graph would change. One of the two traces on the graph would shift so that the two traces overlapped. This would defeat the purpose of placing two conducting loops in the armature. The second loop was added in order to even out the pulsations in the torque.

Question 2

A(n) ____________________ is created when current passes through a conductor and establishes a magnetic field.

Answer 2

electromagnet

Question 3

When drawing the lines that represent the magnetic flux generated by the north and south poles, the convention is for the lines of force to point from ____________________.

Answer 3

north to south

Question 4

The magnetic effects of magnets are concentrated at their poles.

Question 5

Briefly describe the difference between how a generator and a motor work.

Question 6

For any electromagnet, as the current in the conductor increases, the magnetic flux generated by the electromagnet decreases.

Question 7

A magnetic field consists of lines of force, which are called the magnetic flux.

Question 8

When a conductor is passed through a magnetic field, it generates a(n) ____________________.

Question 9

When current exists in a wire that is placed in a magnetic field, the ____________________ effect occurs.

Question 10

In the accompanying figure the conductor will tend to move down.