 # Magnetic force for Edexcel A-level Physics 1. Attraction and repulsion, dipoles
2. Magnetic forces origin
3. Fleming’s left-hand rule
4. Attraction/repulsion of nearby wires
5. Magnetic force

Magnetic forces are non-contact forces. Magnets can be attracted to or repel other magnets. Magnetic forces arise between electrically charged particles due to their motion The direction of a force on a wire in a magnetic force can be found using Fleming's left-hand rule. When two parallel wires are placed close to each other they exert a force of attraction or repulsion on each other, depending on the directions of the currents within the wire. For a conductor at right angles to a magnetic field and carrying a current: F = BIL # 1

A 3m wire in a magnetic field, carrying a current of 12A, experiences a force of 5 N. What is the magnetic flux density? Give the answer to 2 d.p.

0.14 # 2

Fill in the gaps: Electric forces exist between stationary electric charges. Both ... and ... forces exist between moving electric charges.

electric and magnetic # 3

In Fleming's left-hand rule, the thumb points in the direction of the ...?

Movement (force) # 4

Does increasing the current in the wire increase or decrease the force on a given length of wire in a magnetic field?

Increase # 5

A wire is in a 0.07 T magnetic field. It is carrying a current of 28 A and is 2 m long. Calculate the magnetic force on the wire.

3.92 N End of page