Electromagnetic Forces & Induction

The voltmeter is at 0 in this image. How would you manipulate the experiment to create electricity (measured in volts)?

• Flip the magnet around so the North pole is facing out
• Move the magnet back and forth
• Take the magnet out
• Add more coils around the paper cylinder

How could the experimenter increase the amount of electricity being induced by this experiment?

• Increase the number of coils
• Decrease the number of coils
• Flip the magnet around
• Nothing, the amount of electricity cannot be increased

Voltage can be induced in a wire by

• a. moving the wire near a magnet.

• b. moving a magnet near the wire.

• c. changing the current in a wire near a magnet.

• d. all of these

Which activity will produce the highest current?

• Move the magnet bar into the coil while the coil remains stationery

• Move the coil into the magnet bar while the magnet remains stationery

• Move the coil and magnet towards each other

• Move the coil and magnet away from each other

In electromagnetic induction, what is being created?

• Magnetism

• Electrical energy

• Mechanical energy

• Chemical energy

A generator is used to light a bulb.  Energy for lighting the bulb actually comes from a

• coil or wire
• mechanical intput to the generator
• magnet in the generator
• plug where the generator is connected to the wall

Electric charges must ___ in order to create an observable magnetic field.

• exist

• be moving

• be stationary

• disappear

Which of the following will increase the strength of an electric generator? (Select all choices that are true.)

• Use a Bigger Magnet

• Move the Magnet Slower

• Wrap More Coils

• Use a Bigger Battery

___ Law says that a current produced by an induced emf moves in a direction so that its magnetic field opposes the original change in flux

• Lenz'
• Faraday's
• Ampere's

Which device uses slip rings?

• a cathode-ray tube

• a d.c. generator

• an a.c. generator

• a solenoid