CHASHMA NUCLEAR POWER PROJECT

Six identical resistors are connected in parallel across a 78V source. If the total power dissipated is 84 W, what is the value of each resistor?6084145.6434.6The value of the resistance of the resistor shown is13 , 5% tolerance0.13 k, 5% tolerance1.3 k, 5% tolerance130 K, 10% toleranceAn ideal current source haszeroInternal conductanceInternal resistanceVoltage on no loadRippleThe voltage at A of give figure is-6.29v-4.29v-5.29v-3.29v.

The waveform for the current in a 200 F capacitor is shown in fig. P.1.1.36 The waveform for the capacitor voltage is

Ceq= ?3.5 F1.2 F2.4 F1.6 F

The early effect in a bipolar junction transistor is caused byfast turn-on fast turn-offlarge collector-base reverse bias large emitter-base forward biasMOSFET can be used as acurrent controlled capacitorvoltage controlled capacitorcurrent controlled inductor voltage controlled inductorsThermal runaway is not possible in FET because as the temperature of FET increasesthe mobility decreases the transconductance increasesthe drain current increases none of the aboveA source follower using an FET usually has a voltage gain which isgreater than +100 slightly less than unity but positiveexactly unity but negative about -105. A differential amplifier has a differential gain of 20,000 . CMRR=80 dB. The common modegain is given by2 1 1/2 0The approximate input impedance of the OPAMP circuit which hasRi=10k,Rf=100k,RL=10k 120k110k10kA change in the value of the emitter resistance Re in a differential amplifieraffects the difference mode gain Adaffects the common mode gain Acaffects both Ad and Acdoes not effect either Ad and AcA differential amplifier is invariably used in the i/p stage of all OP-AMPs.This is donebasically to provide the OP-AMPs with a very highCMRR bandwidth slew rate open-loop gainThe effective channel length of a MOSFET in a saturation decreases with increase ingate voltage drain voltage source voltage body voltageWhich of the following is not associated with a p-n junctionjunction capacitance charge storage capacitancedepletion capacitance channel length modulationIn a p-n junction diode under reverse bias , the magnitude of electric field is maximum atthe edge of the depletion region on the p-sidethe edge of the depletion region on the n-sidethe p-n junctionthe center of the depletion region on the n-sideIn a common emitter, unbypassed resister providesvoltage shunt feedback current series feedbacknegative voltage feedback positive current feedbackClass AB operation is often used in power (large signal) amplifiers in order toget maximum efficiency remove even harmonicsovercome a crossover distortion reducing collector dissipationThe bandwidth of an RF tuned amplifier is dependent onQ factor of the tuned o/p circuitQ factor of the tuned i/p circuitQuiescent operating pointQ-factor of the o/p and i/p circuits as well as quiescent operating pointThe MOSFET switch in its on-state may be considered equivalent toresistor inductor capacitor batteryMost of the linear ICs are based on the two-transistor differential amplifier because of itsinput voltage dependent linear transfer characteristichigh voltage gainhigh input resistancehigh CMRRNegative feedback in an amplifierReduces gainIncrease frequency &phase distortionReduces bandwidthIncreases noiseA dc power supply has no-load voltage of 30v,and a full-load voltage of 25v at full-loadcurrent of 1A.Its output resistance & load regulation ,respectively are5 & 20 % 25 & 20 % 5 & 16.7 % 25 & 16.7 %The current gain of a bipolar transistor drops at high frequencies because ofTransistor capacitances High current effects in the baseParasitic inductive elements The early effectThe ideal OP-AMP has the following characteristics.Ri= ,A= ,R0=0 Ri=0 ,A= ,R0=0Ri= ,A= ,R0= Ri=0 ,A= ,R0=The action of JFET in its equivalent circuit can best be represented as aCurrent controlled Current source Current controlled voltage sourceVoltage controlled voltage source voltage controlled current sourceAn ideal OP-AMP is an idealCurrent controlled Current source Current controlled voltage sourceVoltage controlled voltage source voltage controlled current sourceThe cascade amplifier is a multistage configuration ofCC-CB CE-CB CB-CC CE-CCThe most commonly used amplifier in sample & hold circuits isA unity gain non-inverting amplifier A unity gain inverting amplifierAn inverting amplifier with a gain of 10 An inverting amplifiers with a gain of 100Introducing a resistor in the emitter of a common amplifier stabilizes the dc operating pointagainst variations inOnly the temperature only the of the transistorBoth Temperature & None of the aboveVoltage Series feedback (also called series-shunt feedback) results inIncrease in both input & output impedancesDecreases in both input & output impedancesIncrease in input impedance & decreases in output impedanceDecrease in input impedance & increase in output impedanceA P-N junction diode's dynamic conductance is directly proportional tothe applied voltagethe temperaturethe currentthe thermal voltageThe width of depletion layer of a P-N junctiondecreases with light dopingincreases with heavy dopingis independent of applied voltageis increased under reverse bias.In LED, light is emitted becauserecombination of charge carriers takes placediode gets heated uplight falling on the diode gets amplifiedlight gets reflected due to lens actionWhich of the following statements is in-correct for a varactor diodeIt has variable capacitanceIt utilizes transition capacitance of a junctionIt has always a uniform doping profileIt is often used as an automatic frequency control device.The circuit in given figure 55.55 shows a full-wave rectifier. The input voltage is (rms) single phase ac. The peak reverse voltage (in volts) acrossthe diodes D1 and D2 .

100

50

6. A transistor series voltage regulator is called emitter-follower regulator because the emitter of thepass transistor follows theoutput voltageinput voltagebase voltagecollector voltageIn the system shown below, x(t) =(sin t)u(t) In steady-state, the response y(t) will be

The output Y in the circuit below is always 1 whentwo or more of the inputs P, Q, R are 0two or more of the inputs P, Q, R are 1any odd number of the inputs P, Q, R is 0any odd number of the inputs P, Q, R is 1The circuit below implements a filter between the input current Ii and the output voltage vo. Assume that the OP-AMP is ideal. The filter implemented is alow pass filter band pass filterband stop filter high pass filterThe point P in the following figure is stuck at 1.The output f will be

A

A 2 mH inductor with some initial current can be represented as shown below,where s is the Laplace Transform variable. The value of initial current is0 A0.5 A1.0 A2.0 A

For the circuit shown in the following figure, the capacitor C is initially uncharged. At t = 0 the switch S is closed. The Vcacross the capacitor at t = 1 millisecond is:0 V6.3 V9.45 V10 VFor the circuit shown, assume that the zener diode is ideal with a breakdown voltage of 6 volts. The waveform observed across R is

6 V12 V 12 V 6 V

C

BAD

An analog signal is band-limited to 4 kHz, sampled at the Nyquist rate and the samples are quantized into 4 levels. The quantized levels are assumed to be independent and equally probable. If we transmit two quantized samples per second, the information rate in Bits/second is:1234In the circuit shown below, the Norton equivalent current in amperes with respect to the terminals P and Q is6.4 j 4.8 6.56 j 7.8710 + j 0 16 + j 0

The diodes and capacitors in the circuit shown are ideal. The voltage v(t) across the diode D1 iscos (t) 1 sin(t)1 cos (t) 1 sin(t)

In the adjacent circuit, the current through the inductor is2A/(1+j)-1A/(1+j)1A/(1+j)0AThe impedance looking into nodes 1 and 2 in the given circuit (figure shown below) is50 100 5 k10.1 kPage 1 of 11