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JNTU ONLINE EXAMINATIONS [Mid 2 - ECA]

1. A parallel tuned circuit is also known as

a. matchedcircuitb. notchcircuitc. resonant circuitd. anti resonant circuit

2. In tuned amplifiers equivalent circuits, the model usedfor transistoris a. hybrid - b. Thevinen'sc. yparameterd. zparameter

3. What factors govern the selectivity of a single tuned amplifier ?a. resonant frequency and gainb. quality factor and bandwidthc. quality factor andgaind. gain andbandwidth

4. The harmonic distortion of an ideal tuned amplifier isa. unityb. zeroc. infinity

d. depends on tuned circuit

5. Higher quality factor of a single tuned amplifier provides aa. higher selectivity andbandwidthb. smaller selectivity and bandwidthc. higher selectivity and smaller bandwidthd. smaller selectivity and higher bandwidth

6. The function of tuned circuit in Tuned Amplifier isa. allows only dc signalb. reject dc and allow all frequenciesc. selecting a particular frequency and rejecting all other frequenciesd. passing all frequencies

7. In tuned amplifiers, harmonic distortion is very small because, at thesefrequenciesa. the impedance is high andgain is lowb. the impedance islow and gain is highc. the impedance and gain of the amplifier becomes highd. the impedance and gain of the amplifier becomes negligible

8. If the quality factor of a resonant circuit of tuned amplifier is doubled then thebandwidth isa. doubledb. samec. halvedd. zero

9. The Band width of an ideal tuned amplifier isa. unityb. zeroc. infinityd. depends on tuned circuit

10. The drawbacks of a single tunedamplifier are

a. wider bandwidth and the sides of gain versus frequency curve are steeperb. wider bandwidth and the sides of gain versus frequency curve are not steeperc. narrow bandwidth and the sides of gain versus frequency curve are notsteeperd. narrow bandwidth and the sides of gain versus frequency curve are steeper

11. The tapping of inductance of tuned circuit of a tapped single tuned capacitancecoupled amplifiera. increases the impedance ofresonant circuitb. increases theoperating frequencyc. increases the resonant frequencyd. reduces the impedance of resonant circuit

12. In the tapped single tuned capacitance coupled amplifier the output voltagewhen the coil is tappeda. (1-n) times of the voltage developed across thecomplete coilb. n times of the voltage developed across thecomplete coilc. same as the voltage developed across the complete coil

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d. half of the voltage developed across the complete coil

13. Tapping in the LC tuned circuit is used toa. reduce the impedance of the LC circuit to match the low impedanceofthe CE amplifierb. increase the impedance of the LC circuit to match the low impedanceof the CE amplifier c.reduce the impedance of the LC circuit to match thehigh impedance of the CE amplifier d.increase the impedance of the LC circuit to match the high impedance of the CE amplifier

14. In tapped single tuned capacitance coupled amplifier, the expression for L to transfermaximum power is

a.

b.

c.

d.

15. The tapping point in a tapped single tuned capacitance coupled Amplifier divide the inductance L into two part

such that

a. L1= 2L and L2 =L/2

b. L1= ( n-1)L and L2 =(1-n)L

c. L1=nL and L2 =(1-n)L

d. L1=n/L and L2 =(1-n)/L

16. The total input circuit capacitance in a single tuned capacitive coupled amplifier is

a.

b.

c.

d.

17. The gain bandwidth product of single tunedamplifier is

where C is total capacitance

a.

b.

c.

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d.

18. The gain bandwidth product of a single tuned capacitive couple amplifier is

a. depends on transconductance and independent on total inputcircuit capacitanceb. depends on both transconductance and total inputcircuit capacitance

c. independent on both transconductance and total inputcircuit capacitanced. independent on transconductance and dependent on total inputcircuit capacitance

19. The LC tuned circuit of single tuned capacitive coupled amplifier is not connectedbetween collector and groundbecause

b. inductorc. transistorcollectord. capacitor

21. In a single tuned transformer coupled amplifier, the output is taken by

a. capacitivecoupling

b. inductivecoupling

c. resistive coupling

d. frequencycoupling

22. The sharpness of the frequency response curve if the transformer coupled amplifier is depends on thea. impedance of the tunedcircuit

b. resonance frequency oftunedcircuit

c. the gain of thetransistor

d. quality factor of the tunedcircuit

23. In a single tuned transformer coupled amplifier, the effective Q of the entire circuit is(Rtt is the resistance of tapped tuned circuit , L is primary inductance and w0 is resonancefrequency )

a.

b.

c.

d.

24. In a single tuned transformer coupled amplifier, the ratio of voltage gain 'A' at anyfrequency to the voltagegain at resonance 'Ar' is

a.

b.

c.

d.

25. In a single tuned transformer coupled amplifier, the impedance of the output circuit at any frequency is given

a.

b.

c.

d.

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26. In a single tuned transformer coupled amplifier the output of the tuned circuit is coupledtothe next stage oroutput devicethrough a

a. resistor

b. inductor

c. transistorcollector

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b. single tuned resistive coupled amplifierc. Inductively coupled amplifierd. single tuned capacitive coupled amplifier

28. In a single tuned transformer coupled amplifier the matching between two stages is done by

a. coil tappingb. using pad circuits

c. capacitively coupled circuitd. the transformer turns ratio

29. In a single tuned transformer coupled amplifier the maximum transfer of power atresonanceis given when( L is primary inductance and M is mutual inductance)

a.

b.

c.

d.

30. In a single tuned transformer coupled amplifier, under conditions of maximum transform ofpower, total

resistance appearing is shunt with the coil equals

a. R02

b. R0/2

c. R0

d. 2R0

31. If two or more tuned circuits are cascaded and tuned to the same frequency, thenthe overall bandwidtha. decreasesb. increasesc. equal to a single staged. increases by number of stages cascaded

32. What are the advantages of double tuned amplifier over single tuned amplifier?

a. smaller bandwidth product and ideal curve characteristics

b. larger gain bandwidth product and ideal curve characteristicsc. smaller gain bandwidth product and response is flat and40db slope sides

d. larger gain bandwidth product andresponse is flat and 40db slope sides

33. The 3dB bandwidth for double tuned amplifier compared to a single tuned amplifier is

a. smallerb. larger

c. samed. exactly half

34. In double tuned amplifier, the term increases than the bandwidth and overshoot are

( wo is angular frequency, M is mutual inductance Rp & Rs are effective resistance of primaryand secondary

tuned circuits)

a. both increases

b. both decreases

c. increases and decreasesrespectively

d. decreases andincreases respectively

35. The gain bandwidth product of double tuned amplifier is

( wo is angular frequency, M is mutual inductance Rp & Rs are effective resistance of primaryand secondary

tuned

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b.

c.

d.

36. In a double tuned amplifier two inductively coupled tuned circuit per stage tuned tothea. different frequenciesb. one is ten times thantheotherc. one is doublethe otherd. same frequencies

37. The double tuned amplifier uses aa. a one RLC circuitb. pair of mutually inductively coupled coilsc. pair of capacitively coupledcircuitsd. one LC circuit

38. The two tuned circuits in double tuned amplifier acts asa. input and load for the base circuitb. load for the emitter circuit and output circuitc. load for the collector circuit and output circuit

d. input and output circuit

39. The resonant frequency of tuned circuit is made equal to the input frequency thanthetuned circuit offersa. high frequency amplificationb. very high impedance to the output signalc. very high impedance to the input signald. very high gain to the amplifier

40. The gain of double tuned amplifier is compared to a single tuned amplifiera. doubleb. halfc. ten timesd. same

41. The resonant circuit of tuned amplifiers used for the following purpose excepta. to provide properly matching load impedance

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b. reset un wantedharmonicsc. to couple power to load

d. to amplifythesignal

42. Tuned amplifier are used where it is desired to

a. generate a narrow band offrequency signal

b. generate awideband of frequency signal

c. amplify a relatively narrow band offrequenciesd. amplify a wideband offrequencies

43. What is the application of tuned amplifiers?a. amplify the given inputsignal

b. provide the impedance matching betweentransmitterand receiver

c. obtain a desiredfrequency and reject all other frequenciesd. increase the gain and bandwidth

44. In communication receivers the following circuits are useda. regulators

b. RCoscillatorsc. crystaloscillator

d. tunedamplifiers

45. Which of the following circuit is used inRFamplifiersa. tuned amplifiersb. RCoscillatorsc. crystaloscillatord. voltageregulators

46. The following device is used in a radio receivers, to select a particular channel among theall the other channe

a. RCoscillatorb. tuned amplifier

c. voltage regulatord. RCamplifier

47. The following device is used in a TV receivers, to select a particular channel among the allthe other channela. RCoscillator

b. tuned amplifier

c. voltage regulator

d. RCamplifier

48. Double tuned amplifiers are used in the followingapplicationsa. Radio and TV receiversb. Radio and TVtransmittersc. Globalposition systemsd. Radartransmitter

49. Write down the relationship between bandwidth 'B' and effective Q- factor 'Q' are relatedby

( w is resonant frequency of tunedamplifier)a. Q=Bw

b. Q=1/(Bw)

c. B=w/Qd. B=wQ

50. Why tuned amplifiers cannot be used at low frequency?a. the required gainislow

b. the size of L & C are largec. the size of L & C aresmall

d. the required bandwidthis high

51. In a stagger tuned amplifier the bandwidth of two single tuned circuits is displacing at their resonance peaksby an amount

a. to theirbandwidth

b. equal to theirgain

c. of impedance of eachstage

d. equal to LC

52. The gain of a stagger tuned amplifier is

a. verysmallb. very large

c. equal to a singlestage

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54. If the number of stages in stagger tuned amplifier is increased, then the resultant voltage gainis a. decreasesb. increasesc. equal to single staged. number of stages times of single stage

55. In stagger tuned amplifier many tuned amplifiers are cascaded each amplifierstageis tuned to differentfrequencies. This results in

a. decreased gain andbandwidth

b. increasedgain and bandwidth

c. increased gain and decreased bandwidth

d. decreased gain and increased bandwidth

56. In the Stagger tuned amplifier, the successive tuned circuits being tuned to

a. the same frequencyb. slightly different frequencies

c. doubles every alternate circuitd. ten time every successive circuit

57. A tuned amplifier uses a number of single tuned stages in cascade, the successive tunedcircuits being tunedto slightly different frequencies is called

a. cascaded single tunedamplifier

b. double tunedamplifier

c. stagger tuned amplifier

d. tuned class B amplifier

58. The bandwidth of the Stagger tuned amplifier isa. increases because all tuned circuits are tuned to a slightly different frequenciesb. increases because all tuned circuits are tuned to the same frequencyc. decreases because all tuned circuits are tuned to a slightlydifferent frequenciesd. increases because all tuned circuits are tuned to the same frequency

59. The bandwidth for stagger tuned amplifier compared to synchronous tuned amplifier is

a. lower

b. higher

c. same

d. half

60. The pass band for a stagger tuned amplifier isa. narrow peaks andsteepsides

b. flat and40db slope sides

c. flat and steep sidesd. ripples and steep sides

61. In tuned amplifiers, Unilateralization technique is the process to provide a stability byremovinga. resistive effects

b. reactive effectsc. both resistive and reactive effects

d. high frequency components

62. The advantage of mismatching technique compared to neutralization technique is

a. achieving frequency stability for a certain bandof frequencies

b. provide a large feed back between output and input

c. low impedance and low Q for tank circuitd. achieving frequency stability at all frequencies

63. The tuned amplifier is to be stable when the value of Cb'cofa transistoris a. very smallb. verylargec. zerod. infinity

64. Except on of the following methods are used to reduce the instability of tuned amplifiers

a. Neutralization

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b. resistivec. inductived. combination of inductance andcapacitance

67. In tuned amplifier, there is frequency at which tuned input and output circuits remain inductive then there isloop consisting of Li, Lo and Cb'c then the system develops

a. perfect matching isobtained

b. selfsustained oscillations

c. gain is increased to infinity

d. the range of frequency isincreased

68. In tuned amplifier, there is frequency at which tuned input and output circuits remain inductive then there isloop consisting of Li , Lo and Cb'c forms a resonant circuit for which the resonant frequency w0 is

a.

b.

c.

d.

69. In tuned amplifier, there is frequency at which tuned input and output circuits remain inductive then there is lo

consisting of Li , Lo and Cb'c forms a

a. opencircuitb. short circuit

c. resonantcircuit

d. nonresonantcircuit

70. The tuned amplifier bursting into oscillation instead of amplification thus it is said to be

a. oscillatorb. open circuit

c. short circuitd. unstable

71. The ratio of maximum collector power dissipation to output power for a Class-B tunedamplifier is

a.

b.

c.

d.

72. The power dissipation in the Class-B tuned amplifier is increases from 0 toa. Vcc

b.

c.

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c. 50.5%d. 78.5 %

75. The expression for the efficiency of the Class-Btuned amplifier

is a.

b.

c.

d.

76. In a class-B tuned amplifier the output of the tuned circuit is coupled to the next stage oroutput device throug

aa. resistor

b. inductorc. transformer

d. capacitor

77. In a Class-B tuned amplifier, the distortion is reduced by using

a. resistor as aload

b. inductoras a load

c. capacitor as aloadd. tank circuit as a load

78. The Class-B mode of operation means that, the collector current flows in a transistor only forthe a. half the period of ac input cycleb. one fourth the period of ac input cyclec. full period of acinput cycled. operate only in dc input

79. In Class B tuned amplifier the efficiency increases linearly with the output amplitudeV1 and it reaches

its maximum when V1 is equal to the

a. Vccb. 2Vcc

c. Vcc/2

d. in-finity

80. The efficiency of Class- B amplifier isa. decreases linearly with output amplitude

b. increases linearly with output amplitudec. increases non linearly with Vcc

d. decreases non linearly with output amplitude

81. The expression for conduction angle for Class-Ctuned amplifier

is a.

b.

c.

d.

82. The ratio of the amplitude of the fundamental component to the amplitude of the total waveform of a Class-Camplifier is

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a. resistorb. FETc. transistorcollectord. capacitor

84. Why the output power of Class-C tuned amplifier is more?a. the gain of CE circuit is lowb. base current is divided in tuned circuitc. transformer provide high input impedanced. transfer provide low input impedance

85. In Class-C tuned amplifier a tank circuit is used toa. provide a matching between input and output

b. operatethe circuit in wide band of frequenciesc. increase the gain of the transistord. convert a non sinusoidal collector current into a sinusoidal outputvoltage

86. Small signal tuned amplifiers are operated inthe modeof a. class -Ab. class-Bc. class-Cd. class-AB

87. To handled large power, the following tuned amplifier is useda. class -Ab. class -Bc. class -Cd. class -AB

88. Tuned class-C amplifier are also calleda. small signal tuned amplifiersb. large signal tuned amplifiersc. linear circuitamplifiersd. staggertuned amplifiers

89. The commonly used transistor configuration in class-C tuned amplifier isa. common baseb. commonemitterc. common collectord. emitterfollower

90. Why there is no separable bias resistors are used in class-C tuned amplifiersa. common emitter amplifier is usedb. the input signal itself drives the transformer into conductionc. it operates with 100%efficiencyd. it is operate inthe RF range

91. The Q in series compensated circuits increase than the gaina. decreasesb. increasesc. halvedd. remains same

92. The bandwidth of the given amplifier is increases bya. decreasing high frequencyb. increasinglow frequencyc. decreasing capacitanced. increases capacitances

93. For a shunt peaked amplifier, the value of m is more than there isa. lower the frequencyrangeb. nonresonanceoccurs

c. peaking the mid band gaind. overshoot occurs

94. The series compensated circuits are not preferred becausea. there is sudden drop in gain beyond highfrequencyb. there is sudden drop in gainbeyondwith in high frequencyc. the gain fallssmoothlyd. there is no peaking of the mid band gain

95. The shunt compensated circuits are preferred becausea. there is sudden drop in gain beyond high frequencyb. there is sudden drop in gain beyond with in high frequencyc. the gain falls smoothlyd. there is peaking of the mid band gain

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96. The frequency response of a given amplifier can beextendedby a. adding few passive circuitelementsb. increasing the signal frequency

c. increasing theoperating voltage

d. addingtransformer

97. By adding the inductor in series with Vcc and collector, the high frequency response of theamplifier is

a. decreases

b. increases

c. remainssame

d. narrowed

98. If the inductor is not present in the shunt compensated amplifier, thena. the frequency response iswidened

b. the gain increasesc. decouple the twostages

d. the gain will beless

99. In shunt compensated amplifier the capacitor is compensated by

a. capacitor

b. inductor

c. resistor

d. transistor

100. The technique used to increase the high frequency range without changing the valueof C and Rand withoutdecreasing the mid band gain is

a. capacitance is connected in series with theloadresistance

b. a transformer is used tocouplethe load resistance

c. Inductance is connected in series with the loadresistance

d. one more resistor is connected in series with theload resistance

101. The change in regulated load voltage for a specified range of line voltage is calleda. loadregulation

b. lineregulation

c. ripple rejection

d. stabilizationfactor

102. The ripple rejection for regulator can be defined as

( VNL is no load or open circuit voltage of the supply, V FL full load voltage of the supply, VRout is output ripple

and

VRin input ripple)

a.

b.

c.

d.

103. The load regulation of voltage regulator may be expressed as( VNL is no load or open circuit voltage of the supply and VFL full load voltage of the supply)

a.

b.

c.

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a.

b.

c.

d.

105. The change in the regulated output voltage when the load current changes fromminimum to maximum is callea. load regulationb. lineregulationc. ripplerejectiond. stabilization factor

106. The output voltage of an unregulated power supply varies due to change ina. collector voltage

b. transistor operating point

c. input base current of transistor

d. input supply voltage, load resistance and temperature

107. The voltage regulation of voltage regulator may be expressed as( VNL is no load or open circuit voltage of the supply and VFL full load voltage of the supply)

a.

b.

c.

d.

108. For better power supply, the required value of voltage regulation is

a. smallerb. largerc. zerod. infinity

109. The ability of a power supply to maintain a constant output voltage inspite of ac inputvoltage fluctuationsand changes in load resistance is called

a. cut of frequency

b. voltage regulation

c. bandwidth

d. gain

110. The stabilization factor of regulator is defined as

a. variation of output voltage with respect to input frequency

b. variation of input frequencywith respect to input voltagec. variation of output voltage with respect to input voltage

d. variation of output frequency with respect to input voltage

111. The sampling resistor is used in series voltage regulator to

a. to increase the operating frequency

b. controls theamount of feedback

c. reducethe input impedance

d. to increase the output impedance

112. The transistor is used in shunt voltage regulator to

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b. 5c. 10

d. 0.5

b. 25%c. 50%d. 100%

d. 515

126. The constant load current limiting is employed in a

a. low voltage current regulatorcircuits

b. high voltage currentregulator circuits

c. low currentvoltage regulator circuits

d. high current voltage regulator circuits

127. The fold back current limiting is employed in aa. low voltage current regulatorcircuits

b. high voltage currentregulator circuits

c. low currentvoltage regulator circuitsd. high current voltage regulator circuits

128. In the voltage regulators the output is shorted or load current exceeds the set value, thenthe current throughthe series transistors is

a. increases

b. folds back

c. remainssame

d. doubled

129. To limit the power dissipation across the transistor, the input voltage is

a. equal to the impedance ofthe input

b. very high to theoutput voltagec. twice that of the output voltaged. equal to the output voltage

130. In a simple circuit , protection is provided by using a fuse, so that when the

a. low voltageflowsb. highvoltage flows

c. current of low values flowsd. current excess of the rated values flows

131. The Stand by Current Drain is the current drawn by the voltage regulator circuit, when loadcurrent isa. unity

b. zero

c. high

d. infinity

132. The Sense Voltage of the voltage regulator is the voltage betweena. input and outputcurrents

b. input andoutput voltages

c. current sense and current limit terminalsd. voltage sense and current limit terminals

133. The output of a voltage regulator is always

a. AC

b. DC

c. pulsed. triangular signal

134. The ideal value of stability factor of a voltage regulator isa. 0

135. The performance of voltage regulator is better when the value of temperature coefficientand output resistanceare a. both are lowb. both are highc. low and highrespectivelyd. highand low respectively

136. The ideal value of regulation of a voltageregulators isa. 0%

137. The ideal value of Input resistance of a voltage regulators is

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151. The function of error amplifier in IC 723 voltage regulator isa. compares the constant currentpulse and zener voltageb. forces the zener to operate at a fixed pointc. compares the pulse from constant current source andreference amplifierd. compares a sample of output voltage and the reference voltage

152. The error signal generated by error amplifier of IC 723 voltage regulator is controls thea. conduction of series pass transistorb. zener operatingpoint

c. sample of output fromcurrentsourced. referenceamplifier

153. The basic elements of IC723 regulator are ( b )sswitch , pulse generator and voltagesource and filter

a. switch , pulse generator and voltagesource and filterb. voltage reference source, an error amplifier, a series pass transistor and a zenerdiodec. switch, voltage reference source, an error amplifier and control elementd. switch , control element, a currentlimitingtransistor and pulse generator

154. The function of constant current source amplifier in IC 723 regulator isa. provides a current pulse to the zenerb. forces the zener to operate at a fixedpointc. compares the sample of output voltage andreference voltaged. gives the reference voltage to the feed back

155. The IC 723 general purpose regulator can be adjusted for aa. narrow range of negativevoltageb. narrow range of positive andnegative voltage

c. wide range of positive ornegativevoltaged. narrow range of positivevoltage

156. The basic elements of IC regulator area. switch , pulse generator and voltagesource and filterb. voltage reference source, an error amplifier, a series pass transistor and a current limitingtransistorc. switch, voltage reference source, an error amplifier and control elementd. switch , control element, a currentlimitingtransistor and pulse generator

157. All the elements of IC Regulator area. distributedcomponentsb. fabricated at least twochipsc. fabricated on asinglechipd. some are fabricated on a chip andotherare open

158. The disadvantages of IC regulators isa. highperformanceb. small sizec. easy toused. highcost

159. The limitation of IC 723 regulator isa. largesizeb. adjusted for wide range of positive andnegative voltagec. no built thermalprotectiond. highcost

160. The advantage of IC 723 regulator isa. largesizeb. adjusted for wide range of positive andnegative voltagec. no built thermalprotectiond. high cost

161. The expression for the current supplied to the load from 7805 three terminal voltageregulator is

a.

b.

c.

d.

162. A current source circuit using a three terminal voltage regulator can be designed for adesired value by choosin

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b. IQc. VRd. V0

163. The type and output of IC 7908 isa. Positive Voltage Regulator and -8V

b. Positive voltage Regulator and 8V

c. Negative Voltage Regulator and -8V

d. Negative Voltage Regulator and 8V

164. The type and output of IC 7905 is

a. Positive Voltage Regulator and -5V

b. Positive voltage Regulator and +5Vc. Negative Voltage Regulator and -8Vd. Negative Voltage Regulator and 8V

165. The output voltage of 5V from 7805 three terminal voltage regulator requires themaximum input voltage of

a. 5V

b. 10V

c. 35 Vd. 55V

166. IC 7800 area. three terminal, positive voltage regulatorsb. two terminal negative voltageregulatorsc. three terminalnegativevoltage regulatorsd. two terminal positive voltage regulators

167. In T0 220 type plastic package voltage regulators the three pins area. 1-output, 2-ground, 3-input

b. 1-input, 2-ground, 3-outputc. 1-input, 2-output,3-ground

d. 1-ground,2-input, 3-output

168. In T0-3 type Metal package voltage regulator the case is act as a

a. input

b. output

c. groundd. supply

169. IC 7900 area. three terminal, positive voltageregulators

b. two terminal negativevoltage regulatorsc. three terminal negative voltage regulators

d. two terminal positive voltage regulators

170. IC 7805 can be usedas a a.5 Vvoltage source b.

10A currentsource c.

50 Vvoltage source

d. 0.5A current source

171. The linear mode regulators are used for

a. low current applicationsb. medium current applications

c. high voltageapplicationsd. highcurrent applications

172. In the linear mode power supply, the series pass transistor operate in

a. cut off region

b. saturation regionc. active region

d. both cutoff and saturation region

173. The purpose of using the filter circuit in DC to DC converter isa. convert the AC into DC

b. amplify the ACc. reduce the ripple

d. generate the AC

174. A current regulator gives a constant output

a. acvoltage

b. dcvoltage

c. ac currentd. dc current

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a. lowb. highc. same

d. doubled

176. DC to DC converter are used when thea. small AC voltage is required from a large AC voltage

b. large DC voltage is required from small DC voltagec. large DC voltage is required from a largeAC voltage

d. small AC voltage requiredfroma large DC voltage

177. Bu using the following circuits we can make a DC to DC converter

a. oscillator and amplifier

b. transformer and amplifierc. oscillator, transformer, rectifier and filter

d. rectifier and filter

178. The function of oscillator in DC to DC converter is

a. amplify the applied DCb. provide a reference source

c. generate a large AC using low DC drive

d. generate a low AC corresponding to a low DC

179. The purpose of a transformer used in DC to DC converter isa. amplificationb. filtering c.matching d.generation

180. The function of Rectifier in DC to DC converter isa. convert large DC to AC

b. convert a large AC to DCc. filter the ACoutput

d. reducethe ripple

181. The power dissipation of a switching voltage regulators compared to series voltageregulators is

a. very highb. low

c. same

d. doubled

182. The efficiency of a switching voltage regulators compared to seriesvoltage regulatorsis a. highb. lowc. same

d. halved

183. The output voltage of switching regulator is a function ofa. input voltage andfrequency

b. ON andOFFtimesc. ON time and input voltage

d. duty cycle and the input voltage

184. For the given value of input voltage and the time period is constant, then the outputvoltageof switching regulis

a. directly proportional to OFFtimeb. inversely proportional to OFF timec. directly proportional to the ON timed. inversely proportional the ON time

185. For step down switching regulator the average output value compared to input voltage is

a. always lessb. alwayshigherc. samed. always unity

186. The basic elements of switch regulator area. switch , pulse generator and voltage source and filterb. control element and voltagesourcec. switch and controlelement

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188. To improve the efficiency of a switch regulator, the following device is used

a. step-up transformerb. series pass transistor

c. variableresistor

d. variableinductor

189. In switching regulator, the series pass transistor is switched ina. saturationregion

b. activeregion

c. between active and saturation region

d. between cutoff and saturation

190. In Switching regulator, the series pass transistor is switched suchthat it producesa a. pulse width modulated square waveoutputb. pulse width modulated sinusoidal outputc. pulse amplitude modulatedtriangular outputd. frequencymodulated triangular output

191. The series pass transistor of SMPS is switched between cutoff and saturation at a high frequency, which produa

a. pulse widthmodulationb. pulseamplitude modulationc. frequency modulationd. phase modulation

192. What is UPS?a. unique power supply

b. uninterruptable power supply

c. uniform phase shifterd. universal power supply

193. The SMPS operate at

a. any frequency

b. high frequenciesc. very low frequencies

d. tuned to a single frequency

194. The SMPS operate at high frequencies hence

a. it needed bulkycomponentsb. it operate in active region

c. less filtering is requiredd. transformer is required

195. The following are the advantages of SMPS except the

a. better voltageregulationb. lesspower dissipation

c. it can operate under low AC input voltages

d. it is large and complex

196. What is SMPS?a. Single Motor PowerSupply

b. Shunt Mode Power Supplyc. SeriesMode Power Supply

d. Switched Mode Power Supply

197. The advantage of SMPS isa. no transformer at the inputb. expensivec. circuit is complexd. radio frequency due to ON-Off switching

198. Which of the following is not the advantage of SMPSa. transformer at the inputb. operate under low A/C inputvoltagesc. better voltageregulationd. small and compact

199. The control element of SMPS is operated in

cutoff regiononly b. activeregion only

surface metal power supp

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