Self induction

A permanent magnet is quickly introduced into the center of an aluminum closed ring. With this ring ...

• will be attracted to the magnet;

• push away from the magnet;

• remain stationary;

• it will start to rotate about an axis passing through its center.

Determine the inductance of the coil if a 5 V self-induction EMF occurs at a rate of change of current of 10 A / s.

• 5 H

• 0,5 H

• 2 H

• 0,2 H

If you reverse the direction of movement of a magnet influencing a coil, what happens to the current?

• reverses

• increases

• stays same

• decreases

What is the greatest inductance core material out of the following?

• Air

• Copper

• Iron

The symbol and units of inductors are

• L (Henrys)

• C (Conductance)

• F (Flux)

• C (Farads)

Inductors...

• oppose change

• like change

The effect on inductance by adding extra coil layers...

• increase L

• decrease L

In order to induce a voltage across a coil ____.

• The coil must be in motion
• Current must be increasing
• There must be relative motion between the coil and the magnetic field
• The coil must be cut by at least 10^8 lines of force per second

Lenz's law states that the induced voltage across an inductor ____. 

• Always opposes the current through the inductor
• Always opposes any change in current
• Changes polarity as current changes direction
• Always opposes the applied votage

An inductor ____.

• All of the above

• Provides a specific value of inductance

• Opposes any change in current

• Stores energy in a magnetic field