Flemings left hand rule and Electric motors 4.7.2.2-3

Question 1

Is magnetic field scalar or vector?

Answer 1

vector

Question 2

How does a motor work?

Answer 2

• when the permanent magnetic field meets the electromagnetic field, they will create a resultant field
• the field in the same direction add, the field in the opposite direction cancel
• resultant fields provide a force that move the wire

Question 3

What angle does current flow at to the magnetic field?

Answer 3

90 degrees to the magnetic field

Question 4

What is Flemings left hand rule?

Answer 4

• your thumb represents magnetic force produced(F)-at 90 degrees
• your pointy finger represents magnetic field(B)-at 90 degrees
• your middle finger represents current(I)-at 90 degrees

Question 5

How can you increase the force?

Answer 5

• increase current
• increase the magnetic flux density(stronger magnet)
• increase the length of the conductor(wire) in the magnetic field

Question 6

How can you reverse the direction of the force?

Answer 6

• reverse direction of current

- change direction of magnetic field

Question 7

What happens if the permanent magnet is in the same direction as the conductor(wire)?

Answer 7

nothing will happen as no force acts on the conductor

Question 8

How does an electric motor work?

Answer 8

• a coil of wire carrying a current in a magnetic field tends rotate
• the force on a conductor in a magnetic field causes the rotation of the coil in an electric motor

Question 9

What causes the rotation in an electric wire?

Answer 9

because the current is flowing through a loop (coil) the current direction is different on either side, which means the force direction on either side, meaning it rotates

Question 10

What are the different parts of an electric motor and what do they do

Answer 10

coil-current passes through it

• brushes-provide connection to battery
• magnets-provides permanent magnetic field
• commutator-reverses the current to keep it rotating
• axle-allows coil to spin
• battery-provides energy