Inv5.Exp3 Text B (pg.231-236)

What does Lenz's Law state about the induced current and magnetic field?

• They are directly proportional to the change in flux

• They oppose the change in flux

• They are unrelated to the change in flux

• They enhance the change in flux

According to Faraday's law, what does the negative sign indicate?

• The induced EMF is in the same direction as the change in flux

• The induced EMF is independent of the change in flux

• The induced EMF is proportional to the change in flux

• The induced EMF opposes the change in flux

How can the magnetic flux through a loop be changed?

• By changing the magnetic field strength only

• By changing the area of the loop only

• By moving the loop closer to a magnetic source

• By rotating the loop or changing its size

What factors affect the size of the induced EMF in a rectangular wire loop?

• The color of the metal bar

• The temperature of the environment

• The magnetic field strength, distance between the rails, and the speed of the moving bar

• The type of metal of the wire

How is the direction of the induced magnetic field determined?

• By the direction of the external magnetic field

• By the direction of the current in the wire

• By the size of the wire loop

• By using the change in area vector

What is an alternative to using a permanent magnet for generating an external magnetic field?

• A resistor

• A capacitor

• A solenoid

• A battery

How can the magnetic field produced by a solenoid be changed?

• By varying the supplied current

• By altering the temperature

• By changing the material of the solenoid

• By painting the solenoid

What enables wireless induction between two solenoids?

• The solenoids being of different materials

• The solenoids being in physical contact

• A constantly changing external magnetic field

• The use of direct current (DC)

According to Lenz’s law, how do the induced current and induced magnetic field react to a change in flux?

• They support the change in flux

• They have no effect on the change in flux

• They amplify the change in flux

• They oppose the change in flux

How can change in field vectors determine the directions of induced fields?

• By using change in velocity vector diagrams

• By using change in acceleration vector diagrams

• By using change in force vector diagrams

• By using change in momentum vector diagrams