Electromagnetism Labowsky

d. oppose a change in the applied magnetic field.

According to Lenz's law, the magnetic field of an induced current in a conductor will

b. alternating current.

An electric current that changes directions at regular intervals is called

b. the two wires will repel each other.

Consider two long, straight, parallel wires, each carrying a current I. If the currents move in opposite directions,

a. the two wires will attract each other.

Consider two long, straight, parallel wires, each carrying a current I. If the currents move in the same direction,

c. magnetic field.

A current can be induced in a closed circuit without the use of a battery or an electrical power supply by moving the circuit through a

d. form circles that go around the wire.

A current in a long, straight wire produces a magnetic field. These magnetic field lines

a. domain; no

A microscopic magnetic region composed of a group of atoms whose magnetic fields are aligned in a common direction is called a(n) ____. In most materials, when these groups are randomly distributed, the substance will show ____ magnetism.

d. all of the above A changing magnetic field induces an electric field perpendicular to the magnetic field. A changing electric field induces a magnetic field perpendicular to the electric field. Changing electric and magnetic fields produce a transverse wave that is perpendicular to both of the oscillating fields.

How does an electromagnetic wave propagate itself?

c. line up mainly in one direction.

In a magnetized substance, the domains

a. domain alignment persists after the external magnetic field is removed.

In a permanent magnet,

d. The material returns to an unmagnetized state.

In soft magnetic materials such as iron, what happens when an external magnetic field is removed?

c. the magnetic force acting on a current-carrying wire in a magnetic field.

The operation of an electric motor depends on

b. They are electromagnetic waves.

What do radio waves, microwaves, X rays, and gamma rays all have in common?

a. The magnitude is greatest close to the poles.

Where is the magnitude of the magnetic field around a permanent magnet greatest?

a

Which compass needle orientation in the figure above might correctly describe the magnet's field at that point?

a. mechanical energy to electrical energy

Which conversion process is the basic function of the electric generator?

b. electrical energy to mechanical energy

Which conversion process is the basic function of the electric motor?

d. all of the above Move the circuit loop into and out of a magnetic field. Change the magnetic field strength around the circuit loop. Change the orientation of the circuit loop with respect to the magnetic field.

Which of the following options can be used to generate electricity?

b. Unlike poles repel each other.

Which of the following situations is not true for magnets?

d. all of the above It transfers energy to objects in the path of the electromagnetic waves. It can be converted to other energy forms. It transports the energy of electromagnetic waves.

Which of the following statements about electromagnetic radiation is true?