Magnetic Fields in Solenoids Flashcards

All 6 cards in this deck

What is a solenoid?

A coil of wire that acts as an electromagnet when there is a current in it.

What is the magnetic field like inside a solenoid, and why?

Strong and almost uniform along the centre, because the fields from the individual coils add together.

Why is the magnetic field outside a solenoid weaker than inside it?

The fields from the individual coils cancel each other outside the solenoid.

Give two ways to make the magnetic field of a solenoid stronger.

Increase the current; increase the number of turns on the coil (or add an iron core).

True or false? An electromagnet such as a solenoid stays magnetised after the current is switched off.

False.
It is a temporary magnet — its magnetism can be switched off by switching off the current.

What shape is the magnetic field outside a solenoid?

The same shape as the field around a bar magnet, with a north pole at one end and a south pole at the other.