Ohms Law and Motors Generators and Electromagnets

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 winds

The strength of an electromagnet can be affected by

• changing the current in the wire

• adding more coils

• increasing the mass of the iron core

• All of the above

Tags

NGSS.MS-PS2-5

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.

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

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

Surrounding every magnet is a __________  __________.

• magnetic field
• electrical current
• another magnet
• an enemy

Tags

NGSS.MS-PS2-3

A motor will make electrical energy change into 

• motion energy
• chemical energy
• mechanical energy
• nothing

In large generators in power plants, ___________ rotate inside a coil of wire to produce an electric current.

• Wind
• Water
• Magnets
• Circuits

What two forces are required for generators and electric motors to work? 

• magnetism and thermal 
• electricity and thermal 
• electricity and magnetism 
• magnetism and radiant 

Tags

NGSS.HS-PS2-5

NGSS.HS-PS3-5

What word best fits this definition: A device which converts electrical energy into mechanical energy usually through the rotation of an electromagnet in the field of a stationary magnet.

• armature

• system

• motor

• electromagnet

Tags

NGSS.MS-PS3-5