p4.2

Question 1

Explain two similarities and two differences between the operation of a loudspeaker and the operation of a microphone.

Answer 1

Similarities:
Both have alternating / changing current / p.d. / voltage
Both use coil / magnets / magnetic field
Both have (moving) diaphragms
The frequency of the sound equals the frequency of the current

Differences:
A microphone converts sound (waves) into current / p.d. / electrical signal
A speaker converts current / p.d. / electrical signal into sound (waves)

Question 2

Explain how the precipitator removes the smoke particles when the gases move
upwards through the chimney.

Answer 2

any 3
The metal grid gives the (smoke) particles a charge / gains electrons
The (smoke) particles gain a negative charge
The (smoke) particles are repelled by the metal grid
The (smoke) particles are attracted by / stick to the metal collectors
Opposite charges attract / like charges repel

Question 3

The student varies the current in the wire and uses the number of paperclips picked up by the solenoid as a measure of the strength of the magnetic field