Changing the audio frequency
Interrupting radio signal
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