Changing the audio frequency

Interrupting radio signal

Using microphone

Using microphone

Tubular centrifugal

Clarifier

Sparkler filter

Vacuum leaf filter

Two valence electrons

Three valence electrons

Four valence electrons

Five valence electrons

U.S.A.

U.K.

U.A.E

Japan

Capacitor is used in it

It is used to compare two signals

Difference amplifier yields more than the direct couple amplifier

Frequency of difference amplifier remains flat from zero to high frequency