Analog Electronics - Engineering

Q1:

A two stage amplifier has an upper cutoff frequency of 2 MHz and a lower cutoff frequency of 2 MHz and a lower cut off frequency of 30 Hz. If both stages are similar, their individual upper and lower cut off frequencies respectively are

A 4 MHz and 60 MHz

B 3 MHz and 20 Hz

C 3 MHz and 60 Hz

D 4 MHz and 20 Hz

ANS:B - 3 MHz and 20 Hz

Fl' = Fl * square root(2^1/n - 1) n = no of stages, here it is 2.
Fl' = 30Hz * square root (2^1/2 -1) = 20Hz
Fh = 2Mhz/square root (2^1/2 -1) = 3Mhz