Electromagnetism : Magnetic Effect of Current-carrying Conductor

Soft iron core

• Easily magnetised and demagnetised

• Difficult to be magnetised and demagnetised

Steel core

• Easily magnetised and demagnetised

• Hard to be magnetised and demagnetised

Soft iron core suitable to become temporary magnet ( electromagnetism)

• True

• False

Steel core suitable to be permanent magnet

• True

• False

Magnetic field is a region where magnetic materials experience force

• True

• False

Electromagnet is a temporary magnet produce when a wire coils around soft iron core

• True

• False

To increase magnetic field around the electromagnet ...

• Increase the current

• Decrease number of coils

• Coil around soft iron core

• U- shaped magnet bar

U-shaped iron core is more suitable than straight iron core because

• Straight iron core easily magnetised and demagnetised

• U-shaped has stronger magnetic field

Diagram shows a current flows into a coil.

Which of the following magnetic field around the wire is correct ?

• 
• 
• 
• 

Diagram shows 2 compass L and M to determine the direction of magnetic field around the straight conductor.

Which direction is correct direction for compass L and M?

• L : P

  M : R

• L : S

  M : P

• L : Q

  M : R

• L : P

  M : S