P4.2.2 - Motors

Question 1

How does an electric motor use the motor effect?

Answer 1

To transfer​ electrical energy to kinetic energy.

Question 2

What is used to reverse the direction of the current in the coil every half turn of the coil.​

Answer 2

a split ring commutator

Question 3

How can you increase the speed of a motor?

Answer 3

• increase current in coil​
• increase strength of B-field/magnet​
• have more loops/longer length of wire​

Question 4

What is the role of a split ring commutator?

Answer 4

It reverses the direction of the current in the coil every half turn which keeps the coiling spinning in the same direction

Question 5

In terms of magnetic fields, why does increasing the current increase the force on the coil?

Answer 5

A magnetic field with B-field lines exists around a wire with a current. The larger the current, the greater the B-field line density, so the greater the interaction between wire and permanent magnet

Question 6

Why might some motors use electromagnets rather than permanent magnets?

Answer 6

Electromagnets produce stronger B-fields than permanent magnets, which produces a larger force.​