Electric Motors And Loudspeakers Flashcards
(3 cards)
Explain how a D.C. electrical motor works
A coil is on a spindle and the forces act in opposite directions, this causes the spindle to rotate
The commuter swaps the contacts every half turn so that the motor keeps moving in the same direction
How can you increase the speed of a D.C. electric motor
Increase the current
Increase the turns on the coil
Use a stronger magnetic field
Use a soft iron core in the coil
Explain how loudspeakers work
A.c. Electric signals from an amplifier are fed to a coil of wire in the speaker which is wrapped around the base of a cone
The coil is surrounded by a permanent magnet, so the a.c. Signals cause a force on the coil and make it move back and fourth
These movements make the cone vibrate, creating sound waves which leads to sound
