http://www.indiabix.com/electronics-and-communication-engineering/analog-electronics/088007http://cg.nic.in/bilaspur/ggpbsp3/LAB%0!anuals%0"i#a%0pd$/%lectronics%0&%0'elecommunication%0(eptt%0pd$/%lectronics%0lab)/Analog%0%lectronics%0"i#a.pd$*%+',-. 01. To prevent a DC return between source and load, it is necessary to useA. resistor between source and loadB. inductor between source and loadC. capacitor between source and loadD. either (a) or (b)Answer: Option CCapacitor offers infinite impedance to DC.2. or a base current of 1! "#, what is the value of collector current in common emitter if $dc % 1!!A. 1! "#B. 1!! "#C. 1 m#D. 1! m#Answer: Option C&C % 1! ' 1!! "# % 1 m#.(. )hich of the followin* oscillators is suitable for fre+uencies in the ran*e of me*a hert,-A. .C phase shiftB. )ien brid*eC. /artleyD. 0oth (a) and (c)Answer: Option COnly 1C oscillators are suitable for 2/, ran*e.3. &f the input to the ideal comparator shown in the fi*ure is a sinusoidal si*nal of 4 5 (pea6 to pea6) without any DCcomponent, then the output of the comparator has a duty cycle ofA. 172 B. 17(C. 178 D. 1712Answer & ExplanationAnswer: Option BExplanation:9. # half wave diode circuit usin* ideal diode has an input volta*e 2! sin :t volts. Then avera*e and rms values of output volta*e areA. and 1! 5B. and 1! 5C. and 9 5D. and 9 5Answer: Option B and 5C % !.9 ' 2! % 1! 5.8. #n .C coupled amplifier has an open loop *ain of 2!! and a lower cutoff fre+uency of 9! /,. &f ne*ative feedbac6 with $ % !.1 is used, the lower cut off fre+uency will beA. about 9! /,B. about 9 /,C. about 2.(4 /,D. about ;!.9 /,Answer: Option C amplifier the input impedance is e+ual to the ratio ofA. ac base volta*e to ac base currentB. ac base volta*e to ac emitter currentC. ac emitter volta*e to ac collector currentD. ac collector volta*e to ac collector currentAnswer: Option A&nput is applied to base with emitter *rounded. The input impedance is the ratio of ac base volta*e to ac base current.14. or a system to wor6, as oscillator the total phase shift of the loop *ain must be e+ual toA. @!? B. 39?C. 2;!? D. (8!?Answer: Option DBain of system with J ve feedbac6 % for oscillationbut 5! K !so, that 1 A #0 % ! #0 % 1 !? or (8!?.1@. #n amplifier has a lar*e ac input si*nal. The clippin* occurs on both the pea6s. The output volta*e will be nearly aA. sine waveB. s+uare waveC. trian*ular waveD. (a) or (c)Answer: Option B)hen a sinusoidal volta*e is clipped on both sides it resembles a s+uare wave.2!. The transistor of followin* fi*ure in Li diode with a base current of 3! "# and &C0O % !, if 500 % 85, .> % 2 6H and $% @!, &0M % 2! "# then .0 %A. 2!! 6HB. 289 6HC. 19! 6HD. 1!! 6HAnswer: Option B.21. &n the amplifier circuit of fi*ure hfe % 1!! and hie % 1!!! H. The volta*e *ain of amplifier is aboutA. !.(( B. !.9C. !.88 D. 1Answer: Option D.22. The efficiency of a full wave rectifier usin* centre tapped transformer is twice that in full wave brid*e rectifier.A. True B. alseAnswer: Option B>fficiency of full wave rectifier with centre tapped transformer is sli*htly hi*her than that of brid*e rectifier.2(. Assertion (A): C> amplifier is the most widely used 0IT amplifierReason (R): C> amplifier has ,ero phase difference between input and outputA. 0oth # and . are correct and . is correct e'planation for #B. 0oth # and . are correct but . is not correct e'planation for #C. # is correct . is wron*D. # is wron* . is correctAnswer: Option CThere is 14!? phase difference between input and output.23. Assertion (A): or lar*e si*nal variations an amplifier circuit has to be analysed *raphicallyReason (R): The output characteristics of a transistor is nonlinear.A. 0oth # and . are correct and . is correct e'planation for #B. 0oth # and . are correct but . is not correct e'planation for #C. # is correct . is wron*D. # is wron* . is correctAnswer: Option ALince the characteristics is nonAlinear, *raphical analysis is needed.29. % !.; 5A. 1! m#B. @.( m#C. 1! "#D. @.( "#Answer: Option D.24. &n fi*ure &D % 3 m#. Then 5L %A. 2! 5B. 3.3 5C. !.3 5D. !.33 5Answer: Option B5L % &L.L % 3 ' 1!A( ' 1.1 ' 1!( % 3.3 5.2@. The self bias providesA. stable M pointB. lar*e volta*e *ainC. hi*h input impedanceD. hi*h base currentAnswer: Option ALtable M point is the advanta*e of self bias circuit.(!. &n fi*ure what is value of &C if $dc % 1!!. A. 9 m#B. 9 "#C. 1! m#D. 1! "#Answer: Option CLince &0 % 1!! "#, &C % $&0 % 1! m#.(1. &n fi*ure the saturation collector current isA.B.C.D. none of the aboveAnswer: Option CLince &> &C,.(2. Consider the followin* statements F # clamper circuit1. adds or subtracts a dc volta*e to a waveform2. does not chan*e the waveform(. amplifiers the waveform)hich are correct-A. 1, 2B. 1, (C. 1, 2, (D. 2, (Answer: Option AClamper does not amplify the waveform. /ence 1 and 2 are correct.((. &n fi*ure v1 % 4 5 and v2 % 4 5. )hich diode will conduct-A. D1 onlyB. D2 onlyC. 0oth D1 and D2D. % !, 5>> % 9 5 and 5CC % 1( 5, then .> will be if &>M % 1 m#A. ( 6HB. 3 6HC. 9 6HD. 3.( 6HAnswer: Option D(@. &n class C operation of an amplifier circuit, the collector current e'ists forA. (8!? of input waveB. 14!? of input waveC. more than 14!? of input waveD. less than 14!? of input waveAnswer: Option D&n class C operation output is in the form of short duration pulses.3!. The ChC parameters of the circuit shown in the fi*ure are hib % 29 H, hfb % !.@@@ and hob% 1!A8H The 5olta*e *ain isA. !.@@ B. 1.@4C. 2.! D. 3Answer: Option D=i % 29 J 1!A8 ' !.@@ ' 1!3 29.31. #n e'ponential amplifier has diode in feedbac6 path.A. True B. alseAnswer: Option B&t has resistance in feedbac6 path.32. DC amplifiers have a tendency to be unstable.A. True B. alseAnswer: Option ADue to drift.3(. # half wave diode rectifier has a capacitance input filter. &f input volta*e is 5m sin :t, D&5 isA. 5mB. 2 5mC. ( 5mD. 3 5mAnswer: Option B0ecause capacitor char*e is retained.33. #n amplifier with loop *ain #$ will be more stable for value of #$ asA. !.@9 B. !.;C. 1.2 D. 1.9Answer: Option B# feedbac6 amplifier is stable if loop *ain is less than unity. 2ore less, more stable, hence $ will be more stable.39. Ltudy the circuit of fi*ure and e'amine the followin* statements1. &t is an active low pass finer.2. &t is a second order filter.(. The chan*e in *ain is 3! d07decade.)hich of the above statements are correct-A. 1, 2 and (B. 1 and 2C. 1 and (D. 2 and (Answer: Option AThe circuit is a second order active low pass filter for which *ain is 3! d07decade.38. &n a circuit of fi*ure, 5s % 1! cos(:t) power drawn by the 2H resistor is 3 watts. The power factor isA. !.( B. !.3C. !.8 D. noneAnswer: Option C5s % 1! cos :t,1et & be the current, then D % &2 .& is the rms current. Drms % &2 . 3 &2 % 3 & % 2#.Total power drawn % 5m &m cos N 1! ' 2 cos N % 1! cos NTotal power cannot be determine until value of . % 12 H is *iven.3;. The +uiescent collector current &C, and collector to emitter volta*e 5C> in a C> connection are the values whenA.ac si*nal is ,eroB.ac si*nal islowC.ac si*nal is ne*ativeD.either (a) or (b)Answer: Option AMuiescentAoperation means operation when ac si*nal is not applied.34. &n the opAamp circuit of fi*ure, 5! %A. 5iB. ( 5iC. 9 5iD. !.9 5iAnswer: Option C.3@. i*ure shows the self bias circuit for C> amplifier and its e+uivalent circuit. 500 and .0respectively areA. 1! 5 and 3 6 ohmB. 9 5 and 3 6 ohmC. 2 5 and 3 6 ohmD. 2 5 and 1! 6 ohmAnswer: Option C.*%+',-. 1. i*ure is a 23 5r stabili,ed power supply. The ,ener is 23 5, 8!! m). The minimum ,ener current is 1! m#. Dropervalues . and ma'imum load current areA. (2! H, 1! m#B. 3!! H, 19 m#C. 3!! H, 1! m#D. (2! H, 19 m#Answer: Option DExplanation:2a'. ,ener current %.2a'imum load current % 29 A 1! % 19 m#.2. The open loop *ain of an amplifier is 2!!. &f ne*ative feedbac6 with $ % !.2 is used, the closed loop *ain will beA. 2!! B. 3!.12C. 3.4;4 D. 2.2Answer: Option CClosed loop *ain % .(. &n a class C power amplifier the input si*nal has a fre+uency of 29! 6/,. &f the collector current pulses are !.1 "s wide, the duty cycle of current waveform isA. 9!E B. 29EC. 2.9E D. !.29EAnswer: Option C3. &n fi*ure as the load resistance is chan*edA. the ,ener current remain constantB. the load current remains constantC. the output volta*e remains constantD. the output volta*e and current throu*h R remain constantAnswer: Option DOutput volta*e % 12 5,.9. &n fi*ure, volta*e across .2 % J 1! 5. &f 50> % !.; 5 and 5> % !.; 5 and .> % 1! 6H, current throu*h .> isA. 1 m#B. !.@( m#C. 2 m#D. 1.48 m#Answer: Option B8. # 12 6/, pulse waveAform is amplified by a circuit havin* an Opper cutAoff fre+uency of 1 2/,. The minimum input pulse width that can be accurately reproduced isA. 4(.(( " secB. 1 " secC. !.1 m secD. (.9 m secAnswer: Option Btr % 1!E D: % minimum Dower(D) % 1! tr 1! ' !.(9 " sec % (.9 " sec.M will beA. 9.19 m#B. 9.2 m#C. 9 m#D. @@! m#Answer: Option D&>M % &CM J &0M % @1! "# J @! "# @@! "#.18. &n fi*ure, transistor $dc % 1!! and 1>D volta*e when it is conductin* is 2 5. Then the base current which saturates the transistor isA. 14 m#B. 1.4 m#C. !.14 m#D. !.!14 m#Answer: Option C.1;. &n fi*ure the dc emitter current of each transistor is aboutA. 3 m#B. 2 m#C. ( m#D. 1 m#Answer: Option DTotal. &t divides e+ually between the two transistors.14. The input volta*e for startin* oscillations in an oscillator is caused byA. ne*ative feedbac6B. positive feedbac6C. noise volta*e in resistorsD. a special *eneratorAnswer: Option CThe amplifier in the oscillator amplifies the noise volta*es. /owever phase shift around the closed loop is ,ero at only one fre+uency. Therefore, only this fre+uency appears at output.1@. The current flowin* in a certain DA< Punction at room temperature is 2 ' 1!A; #mp. )hen a lar*e reverse biased volta*e is applied. Calculate the current flowin* when !.1 volts is applied.A. @ "#B. 1! "#C. 2 "#D. 3 "#Answer: Option A2!. &n followin* fi*ure find 5DLM by assumin* *ate current is ne*li*ible for the pAchannel I>T. (if &DM % A 8 m#, .L % !, 5DD % A14 5, .D % 2 6H, &DLL % A 1! m#, &DO % A ( 5)A. 3 5B. A 8 5C. A 1! 5D. 8 5Answer: Option B0y #pplin* Q51 around drain source loop.5DLM % A14 A (A8). 2 ' 1!( % A 14 J 12 6 ' 1!A( A8 5.21. )hich of the followin* power amplifiers has hi*hest efficiency-A. Class #B. Class #0C. Class 0D. Class CAnswer: Option DClass C has more efficiency than all other classes.22. # full wave rectifier usin* centre tapped transformer and a brid*e rectifier use similar diodes and have e+ual no load output volta*e. Onder e+ual load conditionsA. Output volta*e of brid*e rectifierB. Output volta*e of brid*e rectifier will be more than that of otherC. Output volta*e of both will be e'actly e+ualD. Output volta*e of any one may be more than that of otherAnswer: Option ALince two diodes are in series brid*e rectifier, volta*e drop is more.2(. #ssume that opAamp in fi*ure is ideal. &f input 5i is trian*ular, the output 5! will beA. s+uare waveB. sine waveC. trian*ular waveD. parabolic waveAnswer: Option A&t is a differentiatin* amplifier.23. &n an amplifier with a *ain of A 1!!! and feedbac6 factor $ % A !.1, the chan*e in *ain is 2!E due to temperature. The chan*e in *ain for feedbac6 amplifier will beA. 1!E B. 9EC. !.2E D. !.!1EAnswer: Option C. )hen *ain chan*es, a*e chan*e in29. &n the diode circuit of fi*ure the diodes are ideal. The avera*e current throu*h ammeter isA.B.C.D.Answer: Option B.28. # transistor has two pAn Punctions. The batteries should be connected such thatA. both Punctions are forward biasedB. both Punctions are reverse biasedC. one Punction is forward biased and the other is reverse biasedD. either (a) or (b)Answer: Option C>mitter base Punction is forward biased and baseAcollector Punction is reverse biased.2;. The value of parameter re used in re transistor modelA. increases with increase in temperatureB. decreases with increase in temperatureC. is not affected by increase in temperatureD. either (b) or (c)Answer: Option A.2@. #n opAamp has ,ero *ain for common mode inputs. Then C2.. %A. ,ero B. infiniteC. hi*h D. low24. Assertion (A): &n a full wave rectifier output the lowest ac component is at twice the input fre+uencyReason (R): &n a full wave rectifier, the output waveform consists of half sinusoidsA. 0oth # and . are correct and . is correct e'planation for #B. 0oth # and . are correct but . is not correct e'planation for #C. # is correct . is wron*D. # is wron* . is correctAnswer: Option BLince output consists of half sinusoids, output fre+uency is twice the input fre+uency.Answer: Option BLince common mode si*nal is reduced to ,ero, C2.. is infinite.(!. Assertion (A): T is about 29 "s.A. True B. alseAnswer: Option Bgm is about !.1 ' 1!A( siemens(8. The dissipation at the collector is in the +uiescent state and increases with e'citation in the case of aA. class # series fed #mplifierB. class # transistor coupled #mplifierC. class #0 amplifierD. class 0 amplifierAnswer: Option DOnly one transistor conducts without biasin*.(;. &n followin* circuit, .0 will be if 5CC % 1! 5, 5L % 2 5, .C % 9 6H, .L % @! 6H, $ % 9!, &C>% !, 5C>sat % !.1 5A. 2(! QB. 2(9 QC. 23! QD. 29! QAnswer: Option B0y ma6in* capacitor bloc6ed, &s % !, and applyin* Q510y considerin* Li Transistor.(4. The open loop *ain of an ideal opAamp isA. infiniteB. very hi*hC. neither hi*h nor lowD. lowAnswer: Option A#n ideal opAamp has infinite open loop *ain.(@. &n followin* fi*ure, what will be .1 and .2 for ma'imum symmetrical swin* if 5CLat R !. Biven that .> % 2!! H, .C % 3!! H, 5CC % 2! 5, $ % @@A. 8 6B. ( 6, 8 6C. @.@ 6, 2.3 6D. 2.3 6, @.@ 6Answer: Option D:The +uiescent collector current for ma'imum symmetrical swin*.&n standard consideration, a factor of 1! used as the mar*in of ine+uality for $ independence. Then, 500 % 50>M J &CM . .> !.; J 18.88 ' 1!A( ' 2!! % 3 53!. The ideal characteristics of a stabili,er isA. constant output volta*e with low internal resistanceB. constant output current with low internal resistanceC. constant output volta*e with hi*h internal resistanceD. constant internal resistance and constant output currentAnswer: Option A# stabili,er must *ive constant output volta*e. This is possible only if internal resistance is low.31. The ripple factor of a half wave rectifier is more than 2.A. True B. alseAnswer: Option B.ipple factor of half wave rectifier is 1.21 .32. Assertion (A): The circuit in fi*ure produces repetitive narrow pulses when input is fed with sine or trian*ular waveform havin* pea6 value more than J 5Reason (R): The hi*h *ain opAamp produces volta*es at two levels. &f input is more than J 5, the output is J 19 5 otherwise the output is A 19 5.A. 0oth # and . are correct and . is correct e'planation for #B. 0oth # and . are correct but . is not correct e'planation for #C. # is correct . is wron*D. # is wron* . is correctAnswer: Option A&t is a comparator circuit.3(. &n a C> amplifier drives a low load resistance directly the result will beA. overloadin* of amplifierB. underloadin* of amplifierC. overloadin* or underloadin* of amplifier dependin* on circuitD. none of the aboveAnswer: Option A1ow load resistance means hi*h current and hence over loadin*.33. or C> amplifier of fi*ure, the slope of ac load line isA.B.C.D.Answer: Option Aor ac, .1 and .C appear in parallel./ence .39. or hi*h fre+uencies a capacitor li6eA. an open circuitB. a short circuitC. either open circuit or short circuitD. none of the aboveAnswer: Option B. &f w is very hi*h, SC, is nearly ,ero38. # nonAinvertin* opAamp summer is shown in fi*ure, the output volta*e 5! isA.B. ( sin (1!!t)C. sin (1!!t)D. 2 sin (1!!t)Answer: Option A&7p volta*e % A1 J 1 J sin :t sin :t.3;. &n followin* fi*ure find 5BB by assumin* *ate current is ne*li*ible for the pAchannel I>T. (if &DM % A 8 m#, .L % !, 5DD % A14 5, .D % 2 6H, &DLL % A 1! m#, &DO % A ( 5)A. !.8; 5B. 8.; 5C. ; 5D. !.( 5Answer: Option A&f Bate current is considered to be ne*li*ible then 5BB % 5BLMand .34. # difference amplifier usin* opAamp has closed loop *ain % 9!. &f input is 2 5 to each of invertin* and nonAinvertin* terminals, output is 9 m#. Then C2.. %A. 2!!!! B. 2!!!C. 2!! D. 2!Answer: Option A.3@. The couplin* capacitor in amplifier circuitsA. affects dc biasin*B. does not affect dc biasin*C. affects dc biasin* to some e'tentD. both (a) and (c)Answer: Option BCapacitor is openAcircuit for dc. *%+',-. 31. # full wave rectifier circuit usin* centre tapped transformer and a brid*e rectifier are fed at 1!! 5, 9! /,. The fre+uencies of outputs in these two rectifiers areA. 1!! /, eachB. 9! /, eachC. 1!! /, and 9! /,D. 9! /, and 1!! /,Answer: Option A:Output wave in each case has two cycles for one cycle of input wave.2. )hen the ac base volta*e in a C> amplifier circuit is too hi*h, the ac emitter current isA. ,ero B. constantC. alternatin* D. distortedAnswer: Option D# hi*h si*nal causes distortion because vAi characteristics of 0IT is nonAlinear.(. )hen load is coupled to class # amplifier throu*h transformer, efficiency decreases.A. True B. alseAnswer: Option BTransformer couplin* increases efficiency.3. The *ain of an >T amplifier can be chan*ed by chan*in*A. rmB. gmC. .dD. none of the aboveAnswer: Option BBain is proportional to gm .9. The open loop *ain of an actual opAamp is about 1!!.A. True B. alseAnswer: Option B .&t is very hi*h.8. &n the circuit fi*ure 1>D will be on when v1 isA. less than 8 5B. more than 8 5C. less than 12 5D. more than 12 5Answer: Option B5olta*e input to invertin* input is. Therefore, vi should be more than 8 5.;. # differential amplifier consists of two C0 amplifiers.A. True B. alseAnswer: Option B&t consists of two C> amplifiers.4. i*ure shows a portion of linear v A i characteristics of diode. &f applied volta*e is J 8 5, the current will beA. 32 m#B. 34 m#C. 91 m#D. 93 m#Answer: Option D.@. # power transistor dissipates 9 ). &f ambient temperature is (!? and case to air thermal resistance is 1!? C7), the case temperature isA. 4!?C B. 2!?CC. (2?C D. (!9?CAnswer: Option A1!. #n .AC coupled amplifier has midAfre+uency *ain of 2!! and a fre+uency response from 1!! /, to 2! 6/,. # ne*ative feedbac6 networ6 with $ % !.2 is incorporated into the amplifier circuit, the 0andwidth will beA. 9! 6/,B. 2! 6/,C. 1!! 6/,D. infiniteAnswer: Option C0.). % f/C A f1C 11. &n fi*ure the ,ener currentA. is always 1(! m#B. may vary between 1! m# and 1(! m#C. may vary between 8! m# and 1(! m#D. is always e+ual to 89 m#Answer: Option B)hen &1 % !, =ener current % 1(! m#, when &1 % 12! m#, ,ener current (t % 1! m#).12. &n a commercially available *ood power supply the volta*e re*ulation is aboutA. 1E B. 9EC. 1!E D. 2!EAnswer: Option A# *ood power supply does not allow output volta*e to vary by more than 1E .1(. &n the circuit of fi*ure the diodeA. will conduct as the whole cycleB. will conduct in the positive half cycleC. will not conductD. will conduct from (!? to 19!? in the positive half cycleAnswer: Option CDiode will always be reverse biased.13. The most commonly used bias in 0IT amplifier circuits isA. volta*e divider biasB. emitter biasC. collector biasD. collector feedbac6 biasAnswer: Option A5olta*e divider bias stabili,es &C.19. &n the circuit of fi*ure, v1 % v2 % 1! 5. ThenA. &1 % &2B. &1 T &2C. &2 T &1D. &1 % !Answer: Option CCurrent in diode D2 will be more because resistance in series with D2 is less18. The invertin* opAamp shown in the fi*ure has an open loop *ain to 1!!. The closed loop *iven isA. A4 B. A@C. A1! D. A11Answer: Option D#pplyin* QC1 invertin* node .1;. &n a volta*e re*ulated power supply the ,ener operates in the brea6down re*ion when (5in is input volta*e and 5z is ,ener brea6down volta*e)A. 5in U 5zB. 5in T 5,C. 5in % 5zD. both (a) or (b)Answer: Option B=ener brea6down when input volta*e is more than ,ener brea6down volta*e.14. The parameter h11 for C0 circuit is hi*her than that for C> circuit.A. True B. alseAnswer: Option B&t is lower.1@. i*ure shows a self bias circuit for >T amplifier, &D % 3 m#. Then &L %A. 3 m#B. 2 m#C. !.3 m#D. !.2 m#Answer: Option ALince *ate current is ne*li*ible &L % &D % 3 m#.2!. &n the C> e+uivalent circuit of fi*ure, the volta*e *ain isA. 2!! B. 3!C. 9 D. 1!!!Answer: Option A21. &n a C> amplifierA. both ac and dc load lines have the same slopeB. the ac load line has more slope than dc load lineC. the ac load line has less slope than dc load lineD. the two load lines may have slope more than the otherAnswer: Option BLince ac collector resistance is less than dc collector resistance, slope of ac load line is more than that of dc load line.22. The volta*e *ain of an amplifier without and with feedbac6 are 1!! and 2!. The ne*ative feedbac6 isA. 3E B. 9EC. 2!E D. 4!EAnswer: Option A or $ % !.!3 or 3E .2(. &n the circuit shown in fi*ure, .C % 1!6, .> % 19!H, $ % 1!!, & % 1 m#. The value of, will beA. 9! B. 1!!C. 1@2 D. 3!!Answer: Option Ccircuit shown is Darlin*ton #mplifier.Bain .23. Calculate the conductivity of pure silicon at room temperature when the concentration of carriers is 1.8 ' 1!1! per cm(. Ta6e "e % 19!! cm275Asec, "h % 9!! cm275Asec at room temperature,A. 9.12 ' 1!A18B. 9 ' 1!J18C. 1!18D. 9 ' 1!2!Answer: Option AVi % ("e J "n) . e . ni .29. # potential of ; 5 is applied to a silicon diode. # resistance of 1 6H is also connected in series. &f the diode is forward biased, the current in the circuit isA. ; m#B. 8.( m#C. !.; m#D. !Answer: Option B # % 8.( m#.28. )hich of the followin*-A. 5olta*e series feedbac6 and decrease &7D impedance.B. 5olta*e shunt feedbac6 and decrease &7D impedance.C. 5olta*e series feedbac6 and increase &7D impedance.D. 5olta*e shunt feedbac6 and increase &7D impedance.Answer: Option C0ecause sample si*nal is volta*e and feedbac6 si*nal is also volta*e. The drop in .>chan*e the input volta*e at 0ase >mitter Iunction.2;. &n a transistor > mode the collector current with the transistor in cut off re*ion isA. ,eroB. hi*hC. e+ual to saturated valueD. none of the aboveAnswer: Option A)hen transistor is cut off, &C is ,ero.24. Two C> sta*es, 1 and 2 are coupled throu*h a capacitor. 5CC is the same for both. 0ase resistances .01 and .02 aresuch that .01 T .02. ThenA. base currents for both sta*es are e+ualB. base current of sta*e 1 is more than that of sta*e 2C. base current of sta*e 2 is more than that of sta*e 1D. either (b) or (c)Answer: Option CLince .02 U .01, &02 T &01.2@. &n a two sta*e C> amplifier circuit, the ac collector resistance of the first sta*e depends onA. load resistanceB. input impedance of first sta*eC. input impedance of second sta*eD. all of the aboveAnswer: Option CLince the first amplifier is feedin* the second sta*e, the input impedance of second sta*e is the ac collector resistance of first sta*e.(!. &n a C> amplifier the ac cut off volta*e is @ 5 and slope of ac load line is A !.9 m#75. The ac saturation current isA. @ m#B. 3.9 m#C. ( m#D. 14 m#Answer: Option B#C saturation current is cutoff volta*e ' slope of ac load line.(1. or dc the current throu*h couplin* capacitor in C> amplifier circuit isA. very hi*hB. hi*hC. lowD. ,eroAnswer: Option Ddc remains confined within 0IT. Only ac si*nal comes out.(2. &n a C> amplifier the collector resistance is short circuited. The ac output volta*e willA. increasesB. remains the sameC. increases or decreasesD. decreasesAnswer: Option DLince the output is ta6en across collector resistance, shortAcircuitin* collector resistance will decrease output volta*e.((. &n a transistor C> mode, 5CC % J(! 5. &f the transistor is in cut off re*ion, 5C> %A. J(! 5B. J2! 5C. 1! 5D. ,eroAnswer: Option A)hen transistor is in cut off re*ion 5C> % 5CC .(3. The dc load current in a brid*e rectifier circuit is 1! m#. The dc load current throu*h each diode isA. 3! m#B. 2! m#C. 1! m#D. 9 m#Answer: Option DLince both diodes contribute e+ual load current, each diode current is 9 m#.(9. #n inte*ratin* amplifier has resistance in feedbac6 path.A. True B. alseAnswer: Option B&t has capacitance in feedbac6 path(8. The units of transistor h parameters h11 and h22 are the same.A. True B. alseAnswer: Option BThe units of h11 are ohms and units of h22 siemens.(;. Dositive feedbac6 is mainly used inA. oscillatorsB. thyristorsC. volta*e re*ulatorsD. both (a) and (b)Answer: Option D&n oscillators, the oscillations are *enerated due to positive feedbac6. &n thyristors anode current increases due to positive feedbac6.(4. or a 0IT if $ % 9!, &C>O % ( "# and &C % 1.2 m# then &0A. 23 "#B. 2( "#C. 2! "#D. 1! "#Answer: Option A.(@. &n fi*ure, &D % 3 m#. Then 5D %A. 2! 5B. 1! 5C. (! 5D. 1 5Answer: Option B5D % 2! A 3 ' 1!A( ' 2.9 ' 1!( % 1! 5.3!. The main application of enhancement mode 2OL>T is inA. amplifier circuitsB. oscillator circuitsC. switchin* circuitsD. all of the aboveAnswer: Option C. 0ecause of hi*h switchin* speed 2OL>T is very suitable for di*ital circuit.31. # circuit usin* an opAamp is shown in the *iven fi*ure. &t hasA. volta*e series feedbac6B. volta*e shunt feedbac6C. current shunt feedbac6D. current series feedbac632. Assertion (A): &n C> amplifier the emitter is at *round potential for ac si*nalsReason (R): # C> amplifier has near unity volta*e *ainA. 0oth # and . are correct and . is correct e'planation for #B. 0oth # and . are correct but . is not correct e'planation for #C. # is correct . is wron*D. # is wron* . is correct3(. #n oscillator re+uires an amplifierA. with ne*ative feedbac6B. with positive feedbac6C. with either positive or ne*ative feedbac6D. none of the aboveAnswer: Option BDositive feedbac6 is necessary for sustained oscillations.33. # full wave brid*e diode rectifier uses diodes havin* forward resistance of 9! ohms each. The load resistance is also 9! ohms. The volta*e re*ulations isA. 2!E B. 9!EC. 1!!E D. 2!!EAnswer: Option D amplifier circuit the ac volta*e between emitter and *roundA. is very hi*h B. may be hi*h or lowC. is ,eroD. depends on circuit confi*urationAnswer: Option CCommon emitter means emitter at *round potential.8. # 12! 5, (! /, source feeds a half wave rectifier circuit throu*h a 3 F 1 step down transformer, the avera*e outputvolta*e isA. (! 5B. 1(.9 5C. 1! 5D. ;.!; 5Answer: Option B.;. The slew rate of an ideal opAamp isA. very slowB. slowC. fastD. infinitely fastAnswer: Option DLlew rate si*nifies the fastest chan*e which can occurs in output volta*e. &n an ideal opAamp the output can chan*e instantaneously.4. .e*ulation of the DC power supply of 12 5, 1!! m# is the effective resistance of power supply is 2! HA. 22E B. 1(1EC. (!E D. 2!EAnswer: Option D.@. # brid*e diode circuit usin* ideal diodes has in input volta*e of 2! sin :t volts. The avera*e and rms values of output volta*e areA.B.C.D.Answer: Option A.1!. &n the circuit of fi*ure v1 % 4 5 and v2 % !. )hich diode will conduct (#ssume ideal diodes)-A. D1 onlyB. D2 onlyC. 0oth D1 and D2D. sta*es are coupled throu*h a capacitor. To calculate the +uiescent base current of the two transistors, the capacitor is treated asA. open circuitB. short circuitC. neither (a) nor (b)D. either (a) or (b)Answer: Option ACapacitor has infinite impedance for dc.14. &f it is desired to have low output impedance in an amplifier circuit then we should useA. common collector circuitB. common base circuitC. common emitter circuitD. either (b) or (c)Answer: Option ATherefore CC confi*uration is used for impedance matchin*.1@. Benerally the *ain of a transistor amplifier falls at hi*h fre+uencies due to theA. internal capacitance of deviceB. couplin* capacitor at the &7DC. s6in effectD. couplin* capacitor at the O7DAnswer: Option A#t hi*h fre+uency, internal capacitance comes into consideration