magnetism General

A magnetic field is ...

• A field created by a magnet

• A force field created by a magnet

• An invisible force field created by a magnet

• A force created by a magnet

Magnetic field lines are closer together when ...

• Magnets are closer together

• The magnetic field is stronger

• The magnetic field is weaker

• Magnets repel each other

A bar magnet has the strongest field ...

• Everywhere around the magnet is the same field strength

• The centre of the bar magnet makes the stronger field

• The poles make the strongest field

• The North pole only makes the strongest field

Magnetic field lines coming and going

• Move away from North and towards South

• Move away from South and towards North

• Move away from both the North and the South

• Move towards both the North and the South

Magnetic materials are ...

• Iron, Steel, Copper and Aluminium

• Iron, Steel, Gold and Silver

• Iron, Steel, Lead and Platinum

• Iron, Steel, Nickel and Cobalt

Magnetic field lines ...

• Cross (intersect) each other often

• Cross (intersect) only at the poles

• Never cross (intersect) at the poles

• Never (cross) intersect each other

To make an electromagnet stronger we need to ...

• Decrease voltage or number of coils or size of core

• Increase voltage or number of coils or size of core

• Increase voltage but decrease number of coils and size of core

• Increase number of coils but decrease number of coils and size of core

Fleming's left hand rule states that ...

• Thumb= Current, First finger= Field and Second finger=Force

• Thumb= Field, First finger= Force and Second finger=Current

• Thumb= Force, First finger= Field and Second finger=Current

• Thumb= Current, First finger= Force and Second finger=Current

Equations that links force, magnetic flux density, current and length is ...

• F = B x I x L

• F = B x I / L

• F = B / I x L

• F = B x L / I

The motor effect is when ...

• A current acts on a wire

• A field acts on a wire

• A force acts on a wire

• A resistance acts on a wire