Electromagnetic Induction

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 nearby wire.
• d. all of these

A magnet is moved in and out of a coil of wire connected to a high-resistance voltmeter. If the number of coils doubles, the induced voltage 

• quadruples
• doubles
• is the same
• halves

A magnet can move in a coil of wire to produce electricity in which system?

• Generator
• Motor
• Magnet
• Transformer

___ Law says that the Induced current is proportional to the change of magnetic flux 

• Lenz'
• Faraday's
• Ampere's

Which description best applies to Lenz's Law?

• An induced current occurs when a magnet passes through a tube.

• When a change in magnetic field occurs to a coil the direction of current goes in the in the other direction to this change.

• The direction of an induced current is such to align with the change that created it.

• A magnet is a tube is always slowed by its magnetic field.

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

Which device uses electromagnetic induction to convert mechanical energy into electrical energy?

• Electric motor

• Transformer

• Generator

• Battery

In a transformer, if the number of turns in the primary coil is greater than in the secondary coil, what type of transformer is it?

• Step-up transformer

• Step-down transformer

• Isolation transformer

• Variable transformer

The magnitude of induced current is directly proportional to the rate of _____________ linked with the coil

• magnetic field

• number of magnetic field lines

• change of magnetic field

• change of number of magnetic field lines

An induced emf is produced when a magnet is moved into a coil. The magnitude of induced emf does not depend on:

• The speed with which the magnet is moved

• The number of turns of the coil

• The resistivity of the wire of the coil

• The strength of the magnet