Physics: Magnetic Field

How must atoms act to be considered a domain?

Atoms must be aligned in order, rather than randomly scattered around. (They are magnetic)

If currents are going through parallel wires in the same direction, will they repel or attract?

Attract

What is the path of an electron moving perpendicular to a uniform magnetic field?

A circle

How do field lines correlate with North and South poles?

Field lines always go into the South, and out of the north

A current in a long, straight wire produces a magnetic field. What do these magnetic field lines do?

Form circles that go around the wire ( right hand rule, wrapping fingers around wire)

When do you know you can't solve a problem?

If the current is parallel to the magnetic field. It needs to be perpendicular!!

A current in a solenoid with N turns creates a magnetic field inside the solenoid. The magnetic field strength is directly proportional to what?

The number of turns in the loop and the strength of the current

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

The two wires will attract each other

When do you use the left hand for the "right hand rule"

When electrons are involved instead of protons

What is used to show a force is going out of the page? (right hand rule)

When there is a dot in a circle ( You are seeing the tip of the arrow )

What is used to show a force is going into the page? (right hand rule)

When there is an x in a circle ( You are seeing the tail of the arrow )

What happens to the poles of a magnet when you break it in half?

You will be left with two smaller magnets, each with North and South poles

What would the force be if a current were parallel to the magnetic field?

Zero

What is the right hand rule?

- Fingers point in direction of field (arrows) - Thumb is in direction of current flow (arrows on the line) - Palm determines the force (x and dot)

What is a microscopic magnetic region composed of a group of atoms whose magnetic fields are aligned in a common direction called?

Domain

In a permanent magnet, what does the domain do?

Domain alignment persists after the external magnetic field is removed

In most materials, when these groups are randomly distributed, what kind of magnetism will the substance show?

No magentism

Which magnetic pole is at the geographic South Pole of earth?

North

If currents are going through parallel wires in opposite directions, will they repel or attract?

Repel

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

close to the poles ( north and south )