A high gain MESFET packaged device of case-to-channel thermal resistance of the device is 4.5°C/Watt provides 8W RF output power taking 20W DC power. What will be the channel temperature of the device if the case temperature of the device maintained at 55°C?
A. 109°C
B. 145°C
C. 59.5°C
D. 91°C
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What is the percentage reduction in gain of an amplifier due to introduction of 20 dB of negative feedback?
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The rise time of low pass RC Circuit is given by
A. 2.2 RC
B. 30.2 RC
C. 10 RC
D. 20.2 RC
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Transistor in power amplifier is . . . . . . . .
A. An active device
B. A passive device
C. A on-amp
D. A voltage generating device
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Which one of the following conditions would give V
o = 0 in the circuit shown in the figure?
A. R = R1 + R2
B. R = R 1 R 2
C. R = R2 - R1
D. R = R1 ||R2
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For which of the following conditions, the circuit shown below will function as precision full wave rectifier?
A. R1 = R2 = R
B. R1 = R3 = R
C. R2 = 2R1
D. R1 = R2 = R3
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Which one of the following circuits is most suitable as an oscillator at a frequency of 100 Hz.
A. Hartley oscillator
B. Colpitts oscillator
C. Crystal oscillator
D. Twin-T oscillator
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An amplifier has two identical cascaded stages. Each stage has a bandwidth of 20 kHz. The overall bandwidth shall approximately be equal to
A. 10 kHz
B. 12.9 kHz
C. 20 kHz
D. 28.3 kHz
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If an op-amp comparator has a gain of 100, 000, an input difference of 0.2 mV above reference, and a supply of ±12 V. The output will be:
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An amplifier has a signal input voltage Vi of 0.25 V and draws 1 mA from the source. If the amplifier delivers 8 V to a load of 10 mA, the power gain is
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For an Op-Amp phase shift oscillation, the frequency of oscillations is
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An astable multivibrator has . . . . . . . .
A. One stable state
B. Two stable states
C. No stable state
D. None of the above
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For a voltage follower circuit using an op-amp, which of the following is true?
A. both input and output impedance are very large
B. input impedance is very large and the output impedance is very small
C. input impedance is very small and the output impedance is very large
D. both input and output impedance are very small
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In half wave rectifier, if Vi to the diode is 20 sin (ωt), Vdc is
A. 6.37 V
B. 10 V
C. 14.2 V
D. 20 V
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What is the value of Rs required to self bias N-channel JFET with Vp = -10 V, IDSS = 40 mA and VGSQ = -5 V?
A. 250Ω
B. 500Ω
C. 750Ω
D. 1500Ω
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An amplifier has an input power of 2 microwatts. The power gain of the amplifier is 60 dB. The output power will be
A. 6 microwatts
B. 120 microwatts
C. 2 microwatts
D. 2 watts
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The drain gate capacitance of a junction FET is 2 pF. Assuming a common source voltage gain of 20. What is the input capacitance due to Miller effect?
A. 21 pF
B. 40 pF
C. 42 pF
D. 10 pF
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The ripple frequency in a full-wave rectifier is
A. double the input frequency
B. equal to the input frequency
C. half of the input frequency
D. none of these
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In JFET, dynamic drain resistance rd is of the order of
A. 1 KΩ
B. 10 KΩ
C. 10 MΩ
D. 100 MΩ
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The inverting op-amp shown in the figure has an open-loop gain of 100. The closed-loop gain
V s V 0 is
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