Electreomagneticshits Flashcards
1
Q
Split Ring Commutator
A
- A split metal ring
- Connected to conducting brushes, which allow the electric current to pass onto the ring
- The current produces a turning force on the motor
- The force makes the motor rotate in the CLOCKWISE direction
- The current breaks for a fraction of a second, but the motor keeps turning due to momentum
- The current then switches direction, causing the force on the left hand side to still act UPWARDS
- Right downwards
- So by switching the direction of the current the switch ring commutator allows the motor to keep rotating in the same direction
2
Q
How do loudspeakers use the motor effect?
A
- Electromagnet
- Cone
- Coil of wire wrapped around 1 side of cone
- Coil and cone attached to permanent magnet
- Magnetic field generated by permanent magnet interacts with magnetic field produced by the current through the wire
- This causes either repelling or attraction
- The current is alternated, causing an inwards and outwards motion of the cone, which vibrates
- This causes sound waves to be given off
- The frequency of the alternating of the current can increase the pitch of the sound, and increasing the current through the wire can increase the volume of the sound
3
Q
How to increase the induced potential difference
A
- Using a stronger magnetic field
- If we move the wire more rapidly
- If we shape the wire into a coil, and have more coils
