Electromagnets

The strength of an electromagnet can be affected by

• changing the current in the wire

• changing the number of loops in the solenoid

• changing the size of the iron core

• all of the above

Bob made an electromagnet but it was very weak. How can he make it stronger?

• take away a d-cell

• wrap the wire loosely

• use thicker wire

• use less turns

What component becomes a temporary magnet when electricity is flowing through the circuit?

• d -cell
• wire coil
• switch
• core

Tags

NGSS.MS-PS2-3

Samuel Morse, the inventor of the telegraph had a problem.  How can he increase the strength of the electromagnet in his telegraph?

• use thinner wire
• add more d-cells
• add a switch
• wind fewer wraps of wire around core

Tags

NGSS.MS-PS2-3

This is a picture of a simple electromagnet. How can the electromagnet be made stronger?

• Add more coils of wire to the nail.
• Use a smaller battery.
• Reverse the poles of the magnet.
• Remove all the coils and the nail.

Tags

NGSS.MS-PS2-3

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In order for an electromagnet to be formed, an __________ current must pass through a coil of __________ wrapped around an ________ core.

• wire, iron, electric
• electric, wire, iron
• iron, electric, wire
• excited, hair, apple

Tags

NGSS.MS-PS2-3

Any material that attracts iron or materials containing iron is a(n) 

• A. electric generator
• B. solenoid
• C. magnet
• D. magnetic force

Tags

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How do electromagnets differ from regular magnets? 

• A. They  can be turned off and on 
• B. Their polarity can be reversed
• C. Their strength can be changed
• D. All of the above

Tags

NGSS.MS-PS2-3

A compass needle responds to a magnetic field, because the compass needle is a

• A. generator.
• B. motor.   
• C. magnet.
• D. transformer.

Tags

NGSS.MS-PS2-3

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Where does a magnetic field occur in relation to an electrified wire? 

• At either end, but not in the middle
• Only the side closest to source
• Around the entire length of wire
• Only the side furthest from source

Tags

NGSS.MS-PS2-3