Magnetic Forces and Electromagnetism

All permanent magnets have two

• magnetic charges

• magnetic fields

• magnetic needles

• magnetic poles

Like poles on a permanent magnet will

• attract each other

• repel each other

• always interact

• point in the same direction

Tags

NGSS.MS-PS2-5

The magnetic field lines around a bar magnet

• are perfectly straight

• are only perpendicular to the magnet

• spread out from one pole and curve around to the other

• cross back and forth over one another

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NGSS.MS-PS2-5

Which poles on the earth change?

• the North and South

• the magnetic poles

• the geographic poles

• the telephone poles

What is known as the difference between the earth's magnetic pole and its geographic pole?

• magnetic declination

• magnetic difference

• geographic decline

• geographic increase

As earth's magnetic poles move what happens to the magnetic declination of a given location

• it will always remain constant

• it will return to zero

• it will change

• it will always double

Electric currents passing through wires will produce a(n)

• solenoid

• magnet

• magnetic field

• insulator

Tags

NGSS.HS-PS2-5

What makes an electromagnet different than a permanent magnet.....select all that apply

• it can be turned on and off

• it does not need any electricity

• its strength can be increased and decreased

• its polarity can be reversed

Which way will NOT increase the strength of the magnetic field of an electromagent

• increasing the current

• using a stronger ferromagnetic core

• winding the coils closer together

• decreasing the number of loops

Tags

NGSS.MS-PS2-3

What type of materials are needed to create an electromagnet?

• battery, light bulb, plastic straw

• battery, coil of wire, iron core

• generator, iron core, switch

• switch, source of electricity, compass