magnetic fields

Question 1

what is a magnetic field
how to detect a magnetic field

Answer 1

a field surrounding a permanent magnet or a current carrying conductor in which magnetic objects experience a force
can detect a magnetic field using a compass

Question 2

Explain electromagnetism

Answer 2

When a wire carries a current a magnetic field is created round the wire by the electrons moving within the wire ( charged particles)

Question 3

flemings left hand rule

Answer 3

Thumb - force/ motion
First finger - field
SeCond finge - current

Question 4

When is the force on a wire maximum and why

Answer 4

Maximum when the wire is perpendicular to the field as sin 90 is 1

Question 5

Force is directly proportional to what

Answer 5

Current
Length
Sin theta
Magnetic flux density (strength of magnetic field)

Question 6

Experiment to determine magnetic flux density

Answer 6

2 magnets placed on mass balance
Stiff copper wire held between the two poles
Measure L with ruler
Wire connected to ammeter and power supply
With current the balance will experience a downward force (depending which way round the magnets are )
F= mg
F = BIL