Circuits and Resonance Questions and Answers

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Q11
The gain of an inverting op-amp is given by:
  • A Rf/Rin
  • B -Rf/Rin
  • C 1 + Rf/Rin
  • D -1 - Rf/Rin
Answer: Option B
Explanation: Gain = -Rf/Rin for inverting configuration
Q12
In a common emitter amplifier, the phase shift between input and output is:
  • A
  • B 90°
  • C 180°
  • D 270°
Answer: Option C
Explanation: Common emitter provides 180 degree phase shift (inversion)
Q13
What is the main function of a zener diode?
  • A Amplification
  • B Rectification
  • C Voltage regulation
  • D Oscillation
Answer: Option C
Explanation: Zener diodes are used for voltage regulation in reverse breakdown
Q14
The time constant for an RL circuit is:
  • A R/L
  • B L/R
  • C 1/RC
  • D LC
Answer: Option B
Explanation: τ = L/R for RL circuits
Q15
In a full-wave bridge rectifier, how many diodes conduct during each half cycle?
  • A 1
  • B 2
  • C 3
  • D 4
Answer: Option B
Explanation: Two diodes conduct simultaneously in a bridge rectifier
Q16
What is the typical value of β for a common transistor?
  • A 5-10
  • B 50-200
  • C 500-1000
  • D 1000-5000
Answer: Option B
Explanation: β values typically range from 50 to 200 for most transistors
Q17
The knee voltage for a germanium diode is approximately:
  • A 0.1V
  • B 0.3V
  • C 0.7V
  • D 1.0V
Answer: Option B
Explanation: Germanium diodes have about 0.3V knee voltage
Q18
In a series resonant circuit, at frequencies below resonance, the circuit behaves as:
  • A Capacitive
  • B Inductive
  • C Resistive
  • D Open circuit
Answer: Option A
Explanation: Below resonance, capacitive reactance dominates
Q19
What is the purpose of a bypass capacitor in amplifier circuits?
  • A DC blocking
  • B AC bypass
  • C Voltage doubling
  • D Current limiting
Answer: Option B
Explanation: Bypass capacitors provide AC ground for emitter resistor
Q20
The unit of mutual inductance is:
  • A Farad
  • B Henry
  • C Ohm
  • D Siemens
Answer: Option B
Explanation: Mutual inductance is measured in Henry (H)
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