Physics Chapter 24

If a steady magnetic field exerts a force on a moving charge, that force is directed

at right angles to the direction of the motion

Like kinds of magnetic poles repel while unlike kinds of magnetic poles

attract

An electromagnet can be made stronger by

both: increasing the number of turns of wire increasing the current in the coil

Magnetic field lines about a current-carrying wire

circle the wire in closed loops

The magnetic force on a moving charged particle can change the particle's

direction

An electron is shot through a spot somewhere between the ends of a horseshoe magnet. The electron

direction is changed

The source of all magnetism is:

either or both: electrons rotating around an atomic nucleus electrons spinning around internal axes

Compared to the huge force that attracts an iron tack to a strong magnet, the force that the tack exerts on the magnet is

equally huge

Magnetism is due to the motion of electrons as they

move around the nucleus spin on their axes

The source of all magnetism is

moving electric charges

Which force field can increase a moving electron's speed?

only an electric field

The force on an electron moving in a magnetic field will be the largest when its direction is

perpendicular to the magnetic field direction

Where magnetic field lines are more dense, the field there is

stronger

A weak and strong magnet repel each other. The greater repelling force is by the

stronger magnet and weaker magnet

The reason that an electron moving in a magnetic field doesn't pick up speed is

the magnetic force is always perpendicular to its motion.

An iron rod becomes magnetic when

the net spins of its electrons are in the same direction