A change in the value of the emitter resistance Re in a differential amplifier
A. Affects the difference mode gain Ad
B. Affects the common mode gain Ac
C. Affects both Ad and Ac
D. Does not effect either Ad and Ac
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The bandwidth of an RF tuned amplifier is dependent on
A. Q-factor of the tuned output circuit
B. Q-factor of the tuned input circuit
C. Quiescent operating point
D. Q-factor of the output and input circuits as well as quiescent operating point
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Introducing a resistor in the emitter of a common amplifier stabilizes the dc operating point against variations in
A. Only the temperature
B. only the β of the transistor
C. Both Temperature & β
D. None of the above
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The MOSFET switch in its onstate may be considered equivalent to
A. Resistor
B. Inductor
C. Capacitor
D. Battery
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Most of the linear ICs are based on the two-transistor differential amplifier because of its
A. Input voltage dependent linear transfer characteristic
B. High voltage gain
C. High input resistance
D. High CMRR
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The horizontal intercept of dc load line is the same as ideal
A. Cut off point
B. Saturation point
C. Operating point
D. Quasi saturation point
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A 741-type OP-amp has a gain-bandwidth product of 1MHz. A non-inverting amplifier using this OP-amp & having a voltage gain of 20 db will exhibit -3 db bandwidth of
A. 50 KHz
B. 100 KHz
C. 17 1000 KHz
D. 7.07 1000 KHz
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A differential amplifier is invariably used in the input stage of all OP-amps. This is dome basically to provide the OP-amps with a very high
A. CMRR
B. Bandwidth
C. Slew rate
D. Open-loop gain
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The early effect in a bipolar junction transistor is caused by
A. Fast turn-on
B. Fast turn-off
C. Large collector-base reverse bias
D. Large emitter-base forward bias
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In a transistor leakage current mainly depends on
A. Doping of base
B. Size of emitter
C. Rating of transistor
D. Temperature
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Asource follower using an FET usually has a voltage gain which is
A. Greater than +100
B. Slightly less than unity but positive
C. Exactly unity but negative
D. About -10
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Three identical amplifiers with each one having a voltage gain of 50,input resistance of 1KΩ & output resistance of 250, are cascaded. The open circuit voltage gain of combined amplifier is
A. 49dB
B. 51dB
C. 98dB
D. 102dB
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A dc power supply has no-load voltage of 30v,and a full-load voltage of 25v at full-load current of 1A.Its output resistance & load regulation ,respectively are
A. 5 Ω & 20 %
B. 25 Ω & 20 %
C. 5 Ω & 16.7 %
D. 25 Ω & 16.7 %
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In an OP-amp differentiator
A. The amplitude of output is proportional to rate of change of input
B. The amplitude of output is proportional to input
C. Output occurs when input is finite and constant
D. Polarity of input and output is the same
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Class AB operation is often used in power large signal) amplifiers in order to
A. Get maximum efficiency
B. Remove even harmonics
C. Overcome a crossover distortion
D. Reducing collector dissipation
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Which of the following amplifier circuit using junction transistor has the best gain?
A. Common base
B. Common emitter
C. Common collector
D. All have the same gain
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When a transistor is connected in common emitter mode, it with have
A. Negligible input resistance and high output resistance
B. High input resistance and low output resistance
C. Medium input resistance and high output resistance
D. Low input resistance as well as output resistance
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In all base driver amplifiers
A. ac collector voltage is 180° out of phase with ac base voltage
B. ac emitter voltage is 180° out of phase with ac base voltage
C. ac collector voltage is in phase with ac base voltage
D. none of the above
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The effective channel length of a MOSFET in a saturation decreases with increase in
A. Gate voltage
B. Drain voltage
C. Source voltage
D. Body voltage
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Which of the following statements is false?
A. Push pull signals are equal and opposite in phase
B. Class AB operation cannot be used for a push pull audio power output phase
C. A push pull output transformer has a centre-tapped primary
D. All of the above
Select an option to see the answer and solution.