Practice Question

1.State what a solenoid is

Long coil of insulated wire

2. Explain why a solenoid can produce a much stronger magnetic field compared to a wire

Straight wire: When a current flows through a straight wire, it produces a circular magnetic field around it. But this field is relatively weak and spreads out.

Solenoid (coiled wire): When you wrap the wire into a coil, the magnetic fields from each loop of wire add together, especially inside the coil, to make a much stronger, concentrated magnetic field. This creates a field similar to that of a bar magnet.

This is because:

1.Field lines overlap and combine in the same direction inside the coil.

2.This reinforces the field, making it stronger and more uniform inside the solenoid.

3. How do we know which end of the solenoid is the North or the South pole ?

The direction of the current will indicate which end of the solenoid is the North or South pole. 

If the current flows:

Clockwise = South pole

Anticlockwise = North pole

4. Write an experiment to prove how the magetic effect of a current can be demonstrated by using iron filings and a solenoid. 

1.Place a piece of card over the solenoid.

2.Sprinkle iron filings on the card.

3.Switch on the current.

4.Tap the card gently: the iron filings line up along the magnetic field lines.

You will see the field lines emerging from one end of the solenoid and curving around to the other end, just like the magnetic field of a bar magnet.