The amplifiers `X, Y` and `Z` are connected in series. If the voltage gains of `X, Y` and `Z` are `10, 20` and `30`, respectively and the input signal is `1mV` peak value, then what is the output signal voltage (peak value)
(i) if dc supply voltage is 10V ?
(ii) if dc supply voltage is 5V?

Explanation

Given, `A_(v_(x)) = 10, A_(v_(y)) = 20, A_(v_(z)) = 30`,
`DeltaV_(i) = 1 mV = 10^(-3)V`
`("Output signal voltage"(DeltaV_(0)))/("Input signal voltage "(DeltaV_(i))) =` total voltage amplification `=A_(v_(x)) xx A_(v_(y)) xx A_(v_(z))`
or `DeltaV_(0) = A_(v_(x)) xx A_(v_(y)) xx A_(v_(z)) xx DeltaVi = 10 xx 20 xx 30 xx 30^(-3) = 6V`
(i) If d.c. supply voltage is `10V`, then output is `6V` since theretical gain is equal to practial gain, i.e., output can never be greater than `6V`. Hence `V_(0) = 6V`.
(ii) If d.c. supply voltage is `5V`, i.e. `V_(c c) = 5V`, then output peak will not exceed `5V`. Hence, `V_(0) =5V`.