Electronic Circuit Analysis Mid - II, April - 2012

1.Negative feedback in amplifier
  • improves SNR at the input
  • improves SNR at the output
  • Increases distortion
  • None of the above
Answer: B
2.For generating a sinusoidal wave of 1KHz frequency, the most suitable oscillator is ____
  • Hartley
  • Colpitts
  • Wien bridge
  • None of the above
Answer: C
3.The frequency stability of LC oscillator is _______ than RC oscillators.
  • less
  • more
  • either a or b
  • None of the above
Answer: A
4.The gain of an amplifier with feedback is ______.
  • A/1+Aβ
  • β/1+βa
  • β/1-βa
  • A/1-Aβ
Answer: A
5.An important limitation of a crystal oscillator is ________.
  • its low output
  • its high Q
  • less availability of quartz crystal
  • its high output
Answer: A
6.In tuned amplifiers, harmonic distortion is ____________.
  • infinite
  • more
  • less
  • None
Answer: C
7.Double tuned amplifier provides ____ bandwidth than single tuned amplifiers.
  • larger
  • smaller
  • negligible
  • constant
Answer: A
8.Tuned amplifiers can be used in _____.
  • Radar
  • IF amplifiers
  • both a and b
  • None
Answer: C
9.In ____ power amplifier, the output signal varies for a full 3600 of the cycle.
  • Class A
  • Class B
  • Class AB
  • None of the above
Answer: A
10.Maximum theoretical efficiency of Class B push pull amplifier is ___.
  • 25.5%
  • 50%
  • 75%
  • 78.5%
Answer: D
11.The Trans conductance amplifier is also called as _____________.
Answer: Series – Series amplifier (or) Current – Series amplifier
12.In an ideal voltage amplifier, the values of Ri & R0 are _______________________.
Answer: ∞,0
13.The ratio of input impedance with feedback to without feedback is _______.
Answer: 1+Aβ
14.An oscillator using LC tuned circuit has L= 58.6μH & C=300pF, then the frequency of oscillations will be _______________.
Answer: 1200kHz
15.In a RC phase shift oscillator, each RC section provides a phase shift of ____________0.
Answer: 60
16.Thermal resistance of the heat sink will be typically _______.
Answer: 3^0 C/W
17.If output power=20W and the input dc power=60W,then the efficiency of power amplifier is ____________.
Answer: 33.3%
18.In Class B power amplifier, Q-point is set ____________ .
Answer: Near cutoff
19.Small signal tuned amplifiers are operated in ________ mode.
Answer: Class A
20.Parallel tuned circuit is also known as ____________.
Answer: Anti resonant circuit