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1) In a full-wave rectifier using two ideal diodes,Vdc & Vm are the dc & peak values of the voltage respectively across a resistive load. If PIV is the peak inverse voltage of the diode, then the appropriate relationships for this rectifier is____________? a. Vdc = Vm/π, PIV=2Vm b. Vdc = 2Vm/π, PIV=2vm c. Vdc = 2Vm/π, PIV=Vm d. Vdc = Vm/π, PIV=Vm
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2) The most commonly used amplifier in sample & hold circuits is______________? a. A unity gain non-inverting amplifier b. A unity gain inverting amplifier c. An inverting amplifier with a gain of 10 d. An inverting amplifiers with a gain of 100
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3) 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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4) In a CB amplifier the maximum efficiency could be____________? a. 99% b. 85% c. 50% d. 25%
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5) 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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6) 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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7) MOSFET can be used as a__________? a. current controlled capacitor b. voltage controlled capacitor c. current controlled inductor d. voltage controlled inductors
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8) A differential amplifier has a differential gain of 20,000 . CMRR=80 dB. The common mode gain is given by________? a. 2 b. 1 c. 1/2 d. 0
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9) In a common emitter, unbypassed resister provides___________? a. voltage shunt feedback b. current series feedback c. negative voltage feedback d. positive current feedback
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10) If =0.98 ,Ico=6µA and Iβ=100µA for a transistor,then the value of Ic will be______? a. 2.3mA b. 3.2mA c. 4.6 mA d. 5.2mA
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11) The MOSFET switch in its on-state may be considered equivalent to_____________? a. resistor b. inductor c. capacitor d. battery
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12) An npn BJT has gm=38mA/v, cµ =10¯14 F, cπ =10¯13F and DC current gain β0=90.For this transistor fT & fβ are________? a. fT =1.64 x 108 Hz & fβ = 1.47 x 1010 Hz. b. fT =1.47 x 1010 Hz & fβ = 1.64 x 108 Hz c. fT =1.33 x 1012 Hz & fβ = 1.47 x 1010 Hz d. fT =1.47 x 1010 Hz & fβ = 1.33 x 1012 Hz
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13) An amplifier using an opamp with slew rate SR=1v/µsec has a gain of 40db.if this amplifier has to faithfully amplify sinusoidal signals from dc to 20 KHz without introducing any slew-rate induced distortion, then the input signal level must not exceed________? a. 795mV b. 395mV c. 795 mV d. 39.5mV
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14) 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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15) The cascade amplifier is a multistage configuration of__________? a. CC-CB b. CE-CB c. CB-CC d. CE-CC
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16) The encapsulation of transistor is necessary for__________? a. preventing radio interference b. preventing photo-emission effects c. avoiding loss of free electrons d. mechanical ruggedness
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17) 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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