Magnetic fields

A wire carries a current, creating a magnetic field around itself as shown. The current in the wire is:

• Directed to the right

• Directed to the left

• Equal to the magnetic field

• In the same direction as the magnetic field

What does the following represent?

⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗

⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗

⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗⊗

• Multiplied by a billion

• A piece of modern art

• Uniform magnetic field directed into the screen away from you

• Uniform magnetic field directed out of your screen at you

Are the magnetic field lines in the picture correct?

• Yes, because they point from north to south.

• No, because they point from north to south (they're supposed to go the other way).

• Yes, because the North pole is on the left in all pictures.

• No, because the North pole is on the left in all pictures (it's supposed to be on the right).

The strongest part of a magnet is...

• the bars .

• the force field.

• the poles.

• the middle.

What does the following represent?
⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙
⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙
⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙⊙

• A crowd with binoculars
• A bunch of coaxial cables 
• Uniform magnetic field directed into the screen away from you
• Uniform magnetic field directed out of your screen at you

A north pole and a south pole will attract.

• True
• False

What happens when two north poles of a magnet are placed together?

• they repel
• they attract
• they cancel each other out
• the strength of the magnet is doubled

The area of magnetic force around a magnet is known as its _____________.

• magnetic field

• magnetic declination

• magnetic fan lines

• magnetic tan lines

Magnetic field lines always cross.

• True
• False

In this image, matching north poles from two magnets are introduced.  What do you predict will be the outcome?

• There will be no interaction.  The poles of magnets do not have an effect on one another.
• The two north poles will attract each other
• The two north poles will repel each other
• The two magnets will combine and become one magnet