A metal bar is being pushed along two conducting rails that are connected by a stationary wire parallel to the moving bar. What is required to generate a constant current in the bar/rail/wire configuration?  Select two answers:

• An external constant perpendicular magnetic field within the bar/rail/wire configuration.

• An external constant parallel magnetic field within the bar/rail/wire configuration.

• The bar needs to be pushed so that it moves with a constant velocity.

• The bar has to stay stationary.

A square loop of wire with 2 turns and a side length of 1 m is placed in a changing magnetic field. If the magnetic field changes from 2 T to 4 T within 8 seconds, what is the average induced EMF?

• 0.25 V

• 0.5 V

• 0 V

• 2 V

A square loop of wire with 10 turns and a side length of 1 m is placed in a changing magnetic field. If the magnetic field changes from 2 T to 4 T within 8 seconds, what is the average induced EMF?

• 1.25 V

• 2.5 V

• 0 V

• 5 V

Which of the following laws is used to find the direction of the induced current in a loop of wire placed in a changing magnetic field?

• Lenz’s Law

• Faraday’s Law

• Ampere's Law

• Gauss’s Law

What are some similarities between a motor and a generator?

• They both rely on Faraday’s Law.

• Both require an input current to work.

• Both need to be rotated by an external force.

• Ampere’s Law explains the operation of both.

A square loop of wire carries current above in a clockwise direction a straight wire that carries current towards the left. In what direction is the net force on the loop?

• Up

• Down

• Right

• Left

How does the current flow through resistor  behave once switch S is closed?

• From point Y to X

• From point X to Y

• The current oscillates between X and Y

• There is no current through the resistor

A conducting bar travels through magnetic field B at constant velocity v. Which part of the bar has a higher electric potential?

• The top

• The bottom

• Neither

• Electric potential is zero in the bar

What direction is the magnetic field in at point N?

• Up

• Down

• Right

• Left

Lenz’s law concerning the direction of an induced current in a conductor by a magnetic field could be a restatement of?

• Ampere’s Law

• The Law of Conservation of Energy

• Ohm’s Law

• Tesla’s Law