12) An amplifier has two identical cascaded stages. Each stage has a bandwidth of 20 kHz. The overall bandwidth shall approximately be equal to
a) 10 kHz
b) 12.9 Khz
c) 20 kHz
d) 28.3 kHz
13) A class-B push-pull type amplifier with transformer coupled load uses two transistors rated 10W each. What is the maximum power output one can obtain at the load from this circuit ?
14) A relaxation oscillator is one which
a) has two stable states
b) oscillates continuously
c) relaxes indefinitely
d) produces non-sinusoidal output
15)In a single-stage RC coupled common emitter amplifier, the phase shift at the lower 3dB frequency is
16) Which one of the following power amplifiers has the maximum efficiency ?
a) Class A
b) Class B
c) Class AB
d) Class C
17) A triangular-square wave generator uses
a) A sine wave oscillation and a comparator
b) An integrator and a comparator
c) A differentiator and a comparator
d) A sine wave oscillator and a clipper
18) Which one of the following is a wide-band amplifier ?
a) RF amplifier
b) IF amplifier
c) Video amplifier
d) AF amplifier
19) For a given op-amp, CMRR =105 and differential gain =105. What is the common mode gain of the op-amp ?
b) 2 x 105