Grade 9 electromagnets

Which one of the following is correct about electromagnetism?

• a straight wire in an open circuit produces a magnetic field

• the magnetic field produced by a current carrying straight wire is circular

• a straight wire in a closed circuit produces a magnetic field like a bar magnet

• a straight wire that carries a current cannot produce a magnetic field

Tags

NGSS.HS-PS2-5

NGSS.HS-PS3-5

An electromagnet is

• a permanent magnet that can be switched on and off

• a permanent magnet that cannot be switched on and off

• a temporary magnet that can be switched on and off

• a temporary magnet that cannot be switched on and off

Carefully analyse the diagram. Which one of the following is correct?

• A is made of plastic

• D is referred to as a solenoid

• If the + and - of the battery are connected the other way the electromagnet will not work

• B is made of iron

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

Carefully analyse the diagram. The magnetic field produced by the electromagnet will be

• circular

• the same as two bar magnets with S and N poles facing each other

• the same as two bar magnets with S poles facing each other

• the same as a simple bar magnet

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

Which one of the following would not change the strength of an electromagnet?

• switching the + and - terminals of the battery

• changing the number of coils in the solenoid

• changing the voltage supply of the battery

• removing the iron core

Tags

NGSS.MS-PS2-3