BASIC ELECTRONICS MCQs 4
Q. 1 The large signal bandwidth of an opamp is limited by its
- (A) Loop gain
- (B) Slew rate
- (C) Output impedance
- (D) Input frequency
Q. 2 Rectification efficiency of a full wave rectifier without filter is nearly equal to
- (A) 51%
- (B) 61%
- (C) 71%
- (D) 81%
Efficiency of a full wave rectifier is given by [(2Im/ π) 2 x RL] / [(Im/ √2) 2 x (Rf+ RL)] = 81%, when Rg is zero.
Q. 3 When the temperature of a doped semiconductor is increased, its conductivity
- (A) Decreases.
- (B) Increases.
- (C) Does not change.
- (D) Increases or decreases depending on whether it is p- or n-type.
Q. 4 The main characteristics of a Darlington Amplifier are
- (A) High input impedance, high output impedance and high current gain.
- (B) Low input impedance, low output impedance and low voltage gain.
- (C) High input impedance, low output impedance and high current gain.
- (D) Low input impedance, low output impedance and high current gain.
Q. 5 The transconductance, gm, of a JFET is computed at constant VDS , by the following:
Q. 6 The feedback factor βat the frequency of oscillation of a Wien bridge oscillator is
- (A) 3
- (B) 1/3
- (C) 11/29
- (D) – 3/29
Q. 7 In an amplifier with negative feedback, the bandwidth is
- (A) Increased by a factor of β
- (B) Decreased by a factor of β
- (C) Increased by a factor of (1+Aβ)
- (D) Not affected at all by the feedback
Where A = gain of the basic amplifier and β= feedback factor
Q. 8 The 'slew rate' of an operational amplifier indicates
- (A) How fast its output current can change
- (B) How fast its output impedance can change
- (C) How fast its output power can change
- (D) How fast its output voltage can change
When a step input signal is given.
Q. 9 In a clamping circuit, the peak-to peak voltage of the waveform being clamped is
- (A) Affected by the clamping
- (B) Not affected by the clamping
- (C) Determined by the clamping voltage value
- (D) Determined by the ratio of rms voltage of the waveform and the clamping voltage
Q.10 Regulation of a.d.c. power supply is given by
- (A) Product of no-load output voltage and full-load current
- (B) Ratio of full-load output voltage and full-load current
- (C) Change in output voltage from no-load to full-load
- (D) Change in output impedance from no-load to full-load
Q.11 A 'literal' in Boolean Algebra means
- (A) A variable inn its uncomplemented form only
- (B) A variable ORed with its complement
- (C) A variable in its complemented form only
- (D) A variable in its complemented or uncomplemented form
Q.12 In an unclocked R-S flip-flop made of NOR gates, the forbidden input condition is
- (A) R = 0, S = 0
- (B) R = 1, S = 0
- (C) R = 0, S = 1
- (D) R = 1, S = 1
Q.13 The current amplification factor in CE configuration is
- (A) α
- (B) β+ 1
- (C) 1/β
- (D) β
Q.14 A zener diode
- (A) Has a high forward voltage rating.
- (B) Has a sharp breakdown at low reverse voltage.
- (C) Is useful as an amplifier.
- (D) Has a negative resistance.
Q.15 N-channel FETs are superior to P-channel FETs, because
- (A) They have higher input impedance.
- (B) They have high switching time.
- (C) They consume less power.
- (D) Mobility of electrons is greater than that of holes.
Q.16 The maximum possible collector circuit efficiency of an ideal class A power amplifier is
- (A) 15%
- (B) 25%
- (C) 50%
- (D) 75%
Q.17 Negative feedback in an amplifier
- (A) Reduces the voltage gain.
- (B) Increases the voltage gain.
- (C) Does not affect the voltage gain.
- (D) Converts the amplifier into an oscillator.
Q.18 For generating 1 kHz signal, the most suitable circuit is
- (A) Colpitts oscillator.
- (B) Hartley oscillator.
- (C) Tuned collector oscillator.
- (D) Wien bridge oscillator.
Q.19 Phe output stage of an op-amp is usually a
- (A) Complementary emitter follower.
- (B) Transformer coupled class B amplifier.
- (C ) Class A power amplifier.
- (D) Class B amplifier.
Q.20 When a sinusoidal voltage wave is fed to a Schmitt trigger, the output will be
- (A) Triangular wave.
- (B) Asymmetric square wave.
- (C) Rectangular wave.
- (D) Trapezoidal wave.
(BASIC ELECTRONICS MCQs 4)