## Friday, September 14, 2012

### Basic Electronics Objective Questions: Part - 1

[1] Removing bypass capacitor across the emitter leg resistor in a CE amplifier causes
a) Increase in current gain
b) Decrease in current gain
c) Increase in voltage gain
d) Decrease in voltage gain

[2] The minimum number of flip-flops required to construct a mod-75 counter is
a) 5
b) 6
c) 7
d) 8

[3] The important characteristic of emitter-follower is
a) High input impedance and high output impedance
b) High input impedance and low output impedance
c) Low input impedance and low output impedance
d) Low input impedance and high output impedance

[4] When an amplifier is provided with current series feedback, its
a) Input impedance increases and output impedance decreases
b) Input and output impedance both decrease
c) Input impedance decreases and output impedance increases
d) Input and output impedance both increase

[5] The frequency of oscillation of a tunnel-collector oscillator having L= 30μH and C =  300pF is nearby
a) 267 kHz
b) 1677 kHz
c) 1.68 kHz
d) 2.67 kHz

fo = 1/[2π√(LC)]
[6] The control terminal (pin 5) of 555 timer IC is normally connected to ground through a capacitor (0.01μF). This is to
a) Protect the IC from inadvertent application of high voltage
b) Prevent false triggering by noise coupled onto the pin
c) Convert the trigger input to sharp pulse by differentiation
d) Suppress any negative triggering pulse

[7] The fan out of a MOS logic gate is higher than that of TTL gates because of its
a) Low input impedance
b) high output impedance
c) Low output impedance
d) High input impedance

[8] The common collector amplifier is also known as
a) Collector follower
b) Base follower
c) Emitter follower
d) Source follower

[9] In class-A amplifier, the output current flows for
a) A part of the cycle or the input signal
b) The full cycle of the input signal
c) Half the cycle of the input signal
d) 3/4th of the cycle of the input signal