Microphones and transformers

Question 1

How does a moving coil microphone use the generator effect to convert sound waves into electrical signals?

Answer 1

1.Sound waves hit the microphone
2.changes in air pressure cause the microphone diaphragm to oscillate
3.diaphragm and coil vibrates at the same frequency as the sound
larger sounds → bigger vibrations.
4.This induces an potential difference and current with the same frequency and amplitude related to the sound.

Question 2

What is a transformer made of?

Answer 2

A primary and secondary coil wrapped around a soft iron core

Question 3

How does a transformer work?

Answer 3

1.AC flows through the primary coil → creates (induces) an alternating magnetic field in the iron core.
2.which induces a potential difference in the secondary coil.

If connected, current flows in the secondary coil.

Question 4

What is the relationship between voltage and current in a transformer?

Answer 4

Increasing voltage reduces current, so voltage is inversely proportional to current

Question 5

what type of current can transformers only work with

Answer 5

AC

Question 6

how do you build a transformer

Answer 6

1. add an iron core
2. wrap a coil of wire around one side (primary coil)
3. wrap another coil of the opposite side (secondary coil)

Question 7

What is a step up transformer

Answer 7

increases the voltage, it has more turns on the secondary coil than the primary coil

it steps up the voltage

primary coil = 10V in —-> secondary coil = 20V out

Question 8

What is a step down transformer

Answer 8

reduces the voltage, has more turns on the primary coil than the secondary coil

steps down the voltage

primary coil = 10V in —-> secondary coil = 8V out