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Question 1

What are the two types of magnets?

Answer 1

• Natural magnets
• Electromagnets

Question 2

What’s the difference between the two magnets

Answer 2

One is made using electricity

Question 3

What are the symbol and units of flux

Answer 3

Symbol: Φ or φ (Phil)
Unit: Weber (Wb)

Question 4

What are the symbol and units of flux density

Answer 4

Symbol: B
Unit: Tesla (T) or (Wb/m^2)

Question 5

How many poles are there on a magnet

Answer 5

There’s 2 N poles and 2 S poles

Question 6

On the magnet, where would the flux go to and out from

Answer 6

the flux would enter from the south pole and exit from the north pole

Question 7

What is the equation of flux density

Answer 7

Magnetic flux density = magnetic flux / area (B=Φ /A)

Question 8

What are the symbol and units for Area

Answer 8

Symbol: A
Unit: m^2

Question 9

What is the equation for force on a current carrying conductor in a magnetic field

Answer 9

F=BIL
F = force on the conductor in Newton (N)
B = magnetic flux density (T)
I = current flow in conductor (A)
L = length of conductor (m)

Question 10

How to identify ‘motors’ and ‘generators’ with your hands

Answer 10

Left hand: Motor
- thumb = motion
- index = field
- middle = current

Right hand: generator
- thumb = motion
- index = field
- middle = induced emf

Question 11

Who’s rule is the left and right hand method

Answer 11

Fleming’s rule

Question 12

How does a ‘solenoid’ occur

Answer 12

• It occurs when a conductor is formed into a series of turns
• when an emf is applied to the conductor a magnetic field is formed
• if the turns of the conductor are woven around the core it will be identified as a ‘coil’

Question 13

The strength of a magnetic field is dependent on

Answer 13

1. Depends of the length of the conductor, increasing the number of turns strengthening the magnetic field
2. The current running through the coils
3. The type of former that the coil is rapped around

Question 14

what is ‘Electromagnetic induction’

Answer 14

It’s the production of an electric current in a conductor moving through a magnetic field

Question 15

What are the three dependent things need to strengthen an induced emf

Answer 15

1. The size of magnetic field which would make the induced emf’s size to increase
2. If the number of turns were to increase also increasing the size of the induced emf
3. If movement speed were to increase so would the size of the induced emf

Question 16

What is the equation of emf

Answer 16

e = B.I.V
e = Induced emf (V)
B = Magnetic flux density (T)
v = Velocity (ms^-1)