The technique used to transmit audio signals in television broadcast is –

What is the name of the device used to convert sound waves into electrical signals?

What is the name of the unit used to measure frequency?

What is the name of the device used to measure sound intensity?

Before playing the orchestra in a musical concert, a sitarist tries to adjust the tension and pluck the string suitably. By doing so, he/she is adjusting-

Decibel unit is used to measure –