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[1 ] BJT Questions 15.03.2019
[1 ]
BJT Questions 15.03.2019
[2 ]
1.
Which of the following condition is true for cut-off mode?
कट-ऑफ मोड क लिए निमि म स कौि सी सथिनि सही ह
a) The collector current Is zero
किकटर धारा शनय ह
b) The collector current is proportional to the base current
किकटर करट बस करट क समािपािी होिा ह
c) The base current is non zero
आधार करट शनय िही ह
d) All of the mentioned
उपयकि सभी
2.
Which of the following is true for a pnp transistor in active region?
सकरिय कषतर म एक pnp टासिथटर क लिए निमिलिखिि म स कौि सा सही ह
a) CB junction is reversed bias and the EB junction is forward bias
CB सधध पशच अलभिि और EB सधध अगर अलभिि
b) CB junction is forward bias and the EB junction is forward bias
CB सधध अगर अलभिि और EB सधध अगर अलभिि
c) CB junction is forward bias and the EB junction is reverse bias
CB सधध अगर अलभिि और EB सधध पशच अलभिि
d) CB junction is reversed bias and the EB junction is reverse bias
CB सधध पशच अलभिि और EB सधध पशच अलभिि
3.
Which of the following is true for a pnp transistor in saturation region?
सिसति कषतर म pnp टासिथटर क लिए निमिलिखिि म स कौि सा सही ह
a) CB junction is reversed bias and the EB junction is forward bias
CB सधध पशच अलभिि और EB सधध अगर अलभिि
b) CB junction is forward bias and the EB junction is forward bias
CB सधध अगर अलभिि और EB सधध अगर अलभिि
c) CB junction is forward bias and the EB junction is reverse bias
CB सधध अगर अलभिि और EB सधध पशच अलभिि
d) CB junction is reversed bias and the EB junction is reverse bias
CB सधध पशच अलभिि और EB सधध पशच अलभिि
4.
[3 ]
A transistor has emitter current of 8mA and alpha of 0.99. Which of the following could be the collector
current?
टासिथटर म 8mA की उतसिक धारा और 0.99 का अलफा ह। निमिलिखिि म स कौि किकटर धारा हो सकिा ह
A. 7.92mA
B. 5.00 mA
C. 8.1mA
D. 7.84mA
5.
The emitter of transistor is generally doped the heaviest because it-
टासिथटर का एलमटर आमिौर पर सबस भारी डोप करकया िािा ह कयोकरक यह
A. Has to dissipate maximum power
सबस जयादा शसकि वयव करिा
B. Has to supply majority charge carriers to the base आधार को आवश वाहक दिा
C. Is the first region of transistor
टासिथटर का पहिा छतर ह
D. Must possess low resistance
कम परनिरोध होिा चाहहए
6.
For silicon diode, the value of the forward bias voltage typically:
लसलिकॉि डायोड क लिए, आमिौर पर फॉरवड बायस वोलटि का मलय
A. Must be greater than 0.3V
0.3V स अधधक होिा चाहहए
B. Must be greater than 0.7V
0.7V स अधधक होिा ही चाहहए
C. Depends on the width of the depletion region
अवछय परि की चौडाई पर निभर करिा ह
D. Depends on the concentration of the majority carriers
बहसखयक आवश वाहको की सादरिा पर निभर करिा ह
7.
A Zener diode:
A. Has a high forward voltage rating
एक उचच फॉरवड वोलटि रहटग ह
B. Has a sharp breakdown at low reverse voltage
[4 ]
कम ररवस वोलटि पर एक िि बरकडाउि ह
C. Is useful as an amplifier
परवधि क लिए उपयोगी होिा ह
D. Has negative resistance
ऋणआतमक परनिरोध रहिा ह
8.
An ideal diode can be considered as an:
एक आदश डायोड क रप म मािा िा सकिा ह
A. Amplifier
B. Bi-stable switch
C. Oscillator
D. Fuse
9.
In semiconductor terminology, the doping process is of:
अधचािक शबदाविी म, डोपपग परकरिया की ह
A. Purifying semiconductor material
अधचािक पदाि को शदध करिा B. Increasing impurity percentage
अशदधिा परनिशि बढािा C. Removal of foreign atoms
बाहरी परमाणओ को हटािा D. Increasing the bias potential
पवभव बढािा
10.
For transistor action:
टासिथटर करिया क लिए
A. The collector must be heavily doped than the emitter region
किकटर को एलमटर कषतर की िििा म भारी अशधध करिी चाहहए
B. The collector base junction must be forward biased
किकटर बस सधध को अगर अलभिि रहिा चाहहए
C. The base region must be narrow
आधार छतर पििा होिा चाहहए
[5 ]
D. The base region must be N-type material
आधार छतर N-type का होिा चाहहए
11.
A Silicon crystal doped with …….. results in a N-type semiconductor.
एक लसलिकॉि करिथटि क साि …… .. एक एिपरकार अधचािक म पररणाम- A. Phosphorus
B. Indium
C. Boron
D. Aluminium
12.
Intrinsic carrier concentration of silicon at room temperature is about-
कमर क िापमाि पर लसलिकॉि की आिररक वाहक सादरिा करकििी होिी ह
A. 9.65*108/cm3 to 1.08*109./cm3
B. 9.65*109/cm3 to 1.08*1010/cm3
C. 8.65*107/cm3 to 1.01*108/cm3
D. 8.65*1011/cm3 to 1.01*1012/cm3
13.
P-N junction diode is equivalent to a
पी-एि िकशि डायोड एक क बराबर ह
A. Resistor
B. OR logic gate
C. Capacitor
D. NAND logic gate
14.
Half-wave rectification requires…………..in three-phase supply.
A. A single Diode
B. Two Diode
C. Three Diode
D. Four Diode
15.
Choose the correct statement:
[6 ]
सतय किि को चनिए
A. Common base amplifiers give higher power gain than common-emitter amplifier
उभयनिषठ-आधार परवधक उभयनिषठ –उतसिक परवधक की िििा म उचच शसकि पराति करि ह B. In common base amplifier the emitter terminal is common to both input and output circuit
उभयनिषठ-आधार परवधक म एलमटर टलमिि इिपट और आउटपट सकरकट दोिो क लिए उभयनिषठ होिा ह
C. Common –emitter amplifiers give higher power gain than common base amplifiers
उभयनिषठ-उतसिक परवधक उभयनिषठ –आधार परवधक की िििा म उचच शसकि पराति करि ह D. None
16.
The width of the depletion layer/region of P-N junction:
P-N सधध क अवछय परि की चौडाई
A. Decrease with light doping
कम अशपदध करि क साि घटिी ह
B. Increase with heavy doping
भारी अशथदधिा क कारण बढिी ह
C. Is independent of the applied voltage
िाग वोलटि स थवितर ह
D. Is increased under reverse bias
ररवस बायस म वधध करि पर बढिी ह
17
In a Zener diode shunt voltage regulator, the diode regulates as long as it is kept in …………condition.
ििर डायोड शट वोलटि रगिटर म, डायोड िब िक रगिट होिा ह, िब िक करक इस ………… कडीशि म रिा िािा ह
A. Forward bias
B. Reverse bias
C. Loaded
D. unloaded
18.
In properly biased NPN transistor, most of the electrons from the emitter
एिपीएि टासिथटर को ठीक स बायथड करि म, उतसिक स अधधकाश इिकटॉि
A. Recombine with the holes in the base
B. Recombine in the emitter itself
C. Pass through the base to the collector
[7 ]
D. Are stopped by the junction barrier
19.
In a Common Collector amplifier, the voltage gain
एक उभयनिषठ किकटर एमपिीफायर म, वोलटि िाभ
A. Cannot exceed unity
B. Depends on output impedance
C. Is dependent on input signal
D. Is always constant
20.
Full-wave Rectifier has theoretical maximum efficiency of:
पण िरग हदषटकारी की मसकसमम दकषिा करकििी होिी ह
A. 40.6%
B. 81.2%
C. 78.5%
D. 50%
21.
As compared to PNP transistor, NPN transistor are preferred due to:
PNP टासिथटर की िििा म NPN टासिथटर को पसद करकया िािा ह
A. Being economical
B. Having simple operating mechanism
C. Consuming less bias voltage
D. Better high frequency response
22.
In a C-E configuration, an emitter resistor is used for:
C-E कॉसनिगरशि म, एक उतसिक परनिरोध का उपयोग करकया िािा ह: A. Stabilization
B. ac signal bypass
C. collector bias
D. higher gain
23.
For a BJT, for common base configuration the input characteristics is represented by a plot between which
of the following parameters?
[8 ]
BJT क लिए, उभयनिषठ आधार कॉसनिगरशि क लिए इिपट पवशषिाओ को निमिलिखिि मापदडो म स करकसक बीच दवारा दशाया गया ह
a) VBE and IE
b) VBE and IB
c) VCE and IC
d) None of the mentioned
24.
For a BJT, for common base configuration the output characteristics is represented by a plot between which
of the following parameters?
BJT क लिए, सामानय आधार पवनयास क लिए आउटपट पवशषिाओ को निमिलिखिि म स करकस परामीटर क बीच दवारा दशाया गया ह?
a) VBE and IB
b) VCE and IC
c) VCB and IC
d) None of the mentioned
25.
The value of IC is precisely zero when the value of IE is zero.
िब IC का माि शनय होिा ह िो IE का माि शनय होिा ह
a) True
b) False
26.
In a BJT, the outer layers are much more thick as compared to the middle layer.
एक BJT म, बाहरी परि मधय परि की िििा म बहि मोटी होिी ह a) True
b) False
27.
Considering the resistances of emitter, collector and base to be Re, Rc and Rb respectively, which of the
following is the correct statements?
एलमटर, किकटर और बस क परनिरोधो को िमशः Re, Rc और Rb मािकर, निमिलिखिि म स कौि सा सही किि ह?
a) Re > Rb > Rc
b) Rc > Rb > Re
[9 ]
c) Rb > Rc > Re
d) None of the mentioned
28.
In a pnp-BJT, when the E-B junction is forward biased and no voltage is applied across C-B junction, what
happens to the width of the depletion region in the E-B junction?
एक pnp-BJT म, िब E-B junction अगर अलभिि होिा ह और C-B िकशि पर कोई वोलटि िाग िही होिा ह, िो E-B
िकशि म अवछय कषतर की चौडाई का कया होगी ?
a) Increases
b) Decreases
c) Remains same
d) Can’t be determined
29.
What is the typical order of magnitude of the base current for a BJT?
BJT क लिए बस करट का पररमाण करकस कोहट का होिा ह ?
a) 10 -8
b) 10 -9
c) 10 -6
d) 10 -3
30.
The collector current in a BJT is temparature-independent.
BJT म किकटर धारा िापमाि-थवितर ह। a) True
b) False
31.
Given that the collector power dissipation is 300 mW, what is the value of collector current for the collector
to emitter voltage = 12 V?
किकटर शसकि वयय 300 mW हदया गया ह, सगराहक धारा का माि कया होगा यहद सगराहक स उतसिक का पवभव 12 volt हो- a) 50 mA
b) 0 mA
c) 25 mA
d) 100 mA
[10 ]
32.
Given that the collector power dissipation is 300 mW, what is the value of collector to emitter voltage for
collector current = 50 mA?
किकटर शसकि वयय 300 mW हदया गया ह, सगराहक स उतसिक का पवभव का माि कया होगा यहद सगराहक धारा का माि 50 mA ह- a) 6 V
b) 3 V
c) 0 V
d) None of the mentioned
33.
Which operating condition is satisfied by the transistor if it is supposed to function in cut-off region?
यहद कट-ऑफ कषतर म काय करिा ह िो टासिथटर दवारा कौि सी ऑपरहटग सथिनि सिषट ह?
a. VCE > 0
b. VCE = 0
c. VCE < 0
d. VCE = Vcc
34.
Which operating region of BJT enables Emitter-base & Collector-base junctions to undergo perfect short-
circuit configuration ?
BJT का कौि सा ऑपरहटग कषतर एलमटर-बस और किकटर-बस िकशिो को सही शॉट-सकरकट कॉसनिगरशि स गिरि म सकषम बिािा ह
a. Active Region
b. Saturation Region
c. Cut-off Region
d. None of the above
35.
If output of transistor amplifier is 5 V and input of that amplifier is 250 mV than voltage gain will be
यहद टासिथटर एमपिीफायर का आउटपट 5 V ह और उस एमपिीफायर का इिपट वोलटि िाभ कया होगा यहद इिपट वोलटि 250 mV ह
A. 20
B. 5
C. 50
D. 25
36.
[11 ]
If voltage gain of amplifier is 20 and base voltage is 100mV than output voltage of an BJT amplifier will be
यहद एमपिीफायर का वोलटि िाभ 20 ह और बस वोलटि 100 mV ह िो BJT एमपिीफायर का आउटपट वोलटि होगा A. 2 V
B. 20 V
C. 1 V
D. 2 mV
37.
When base-emitter voltage is subtracted from collector-emitter voltage, it gives Value of
िब बस-एलमटर वोलटि को किकटर-एलमटर वोलटि स घटाया िािा ह, िो यह वलय ऑफ दिा ह
A. source voltage
B. collector-base voltage
C. base voltage
D. collector voltage
38.
If internal emitter resistance of BJT is 20 Ω and collector resistor of amplifier is 1200 Ω than voltage gain will be
यहद BJT का आिररक उतसिक परनिरोध 20 Ω ह और एमपिीफायर का किकटर परनिरोधक वोलटि 1200 Ω ह िो पवभव िाभ होगा
A. 60
B. 1200
C. 12
D. 20
39.
In between cutoff and saturation along load line of transistor's operation is
टासिथटर का िोड िाइि कटऑफ और सिसति क बीच म ह िो टासिथटर operate होगा A. cutoff region
B. active region
C. saturation region
D. breakdown region
40.
Amplification is process where smaller signal is used to produce a larger
परवधि वह परकरिया ह िहा छोट लसगिि का उपयोग बडा उतपादि करि क लिए करकया िािा ह
A. phase shift signal
B. frequency shift signal
C. identical signal
D. amplitude shift signal
[12 ]
41.
DC beta is transistor's DC
डीसी बीटा टासिथटर का डीसी ह
A. voltage gain
B. current gain
C. resistor gain
D. power gain
42.
Thermal runaway is_________
िमि पिायि _________
a) an uncontrolled positive feedback
एक अनियतरतरि सकारातमक परनिकरिया b) a controlled positive feedback
एक नियतरतरि सकारातमक परनिकरिया c) an uncontrolled negative feedback
एक अनियतरतरि िकारातमक परनिकरिया d) a controlled negative feedback
एक नियतरतरि िकारातमक परनिकरिया
43.
The thermal runway is avoided in a self bias because_________
The thermal runway एक आतम पवागरह स बचा िािा ह कयोकरक ________
a) of its independence on β
b) of the positive feedback produced by the emitter resistor
c) of the negative feedback produced by the emitter resistor
d) of its dependence on β
44.
Which of the following are true?
a) TJ – TA = θPd
b) TJ – TA = θ/Pd
c) TJ – TA = θ+Pd
d) TJ – TA = θ-Pd
45.
When the power dissipation increases in a transistor, the thermal resistance_________
[13 ]
िब एक टासिथटर म शसकि वयय बढ िािा ह, िो िमि परनिरोध
a) increases
b) cannot be predicted
c) decreases
d) remains same
46.
For a given transistor, the thermal resistance is 8°C/W and for the ambient temperature TAis 27°C. If the transistor
dissipates 3W of power, calculate the junction temperature (TJ).
करकसी हदए गए टासिथटर क लिए, िमि परनिरोध 8 ° C / W ह और पररवश क िापमाि TA is 27 ° C क लिए। यहद टासिथटर 3W शसकि को वयय करिा ह, िो िकशि िापमाि (टीि) की गणिा कर a) 51°C
b) 27°C
c) 67°C
d) 77°C
47.
The condition to be satisfied to prevent thermal runaway?
िमि पिायि को रोकि क लिए सिषट होि की सथिनि- a) ∂PC/∂TJ > 1/ θ
b) ∂PC/∂TJ < 1/ θ
c) ∂PC/∂TJ > 1/ θ
d) ∂PC/∂TJ < 1/ θ
48.
Thermal stability can be obtained by_________
िमि सथिरिा _________ दवारा पराति की िा सकिी ह
a) shifting operating point
b) increasing power supply
c) heat sink
d) decreasing current at collector
49.
The output resistance is given by _________
आउटपट परनिरोध _________ दवारा हदया िािा ह
a) ∆VCE/∆IB
b) ∆VBE/∆IB
c) ∆VBE/∆IC
d) ∆VCE/∆IC
[14 ]
50.
Which of the following cases damage the transistor?
निमिलिखिि म स कौि सा कस टासिथटर को िकसाि पहचािा ह?
a) when VCE is increased too far
िब VCE बहि अधधक बढ िािा ह
b) when VCE is decreased too far
िब VCE बहि अधधक घट िािा ह
c) when VBE is increased too far
िब VBE बहि अधधक बढ िािा ह
d) when VBE is decreased too far
िब VBE बहि अधधक घट िािा ह
51.
The small amount of current which flows even when base current IB=0 is called_________
करट की छोटी मातरा िो करक आधार पर भी परवाहहि होिी ह िब बस करट IB = 0 कहिािा ह
a) IBEO
b) ICBO
c) ICEO
d) IC
52.
A change in 700mV in base emitter voltage causes a change of 200µA in the base current. Determine the dynamic
input resistance.
बस एलमटर वोलटि म 700mV म बदिाव स बस करट म 200µ A पररविि होिा ह। डायिालमक इिपट परनिरोध होगा a) 2kΩ
b) 10kΩ
c) 3kΩ
d) 3.5kΩ
53.
There are …………… h parameters of a transistor
एक टासिथटर क …………… h परामीटर ह A. Two
B. Four
C. Three
D. None of the above
54.
The h parameter approach gives correct results for …………
h parameter दसषटकोण क लिए सही पररणाम दिा ह ………
[15 ]
A. Large signals only
B. Small signals only
C. Both small and large signals
D. None of the above
55.
A transistor behaves as a linear device for ………….
एक टासिथटर ……… क लिए एक रखिक उपकरण क रप म वयवहार करिा ह। A. Small signals only
B. Large signals only
C. Both small and large signals
D. None of the above
56.
The parameter hie stands for input impedance in ………..
A. CB arrangement with output shorted
B. CC arrangement with output shorted
C. CE arrangement with output shorted
D. None of the above
57.
The dimensions of hie parameter are ………..
hie का पवमा कया होिा ह
A. Mho
B. Ohm
C. Farad
D. None of the above
58.
The hfe parameter is called ……………. in CE arrangement with output shorted
hfe परामीटर को …………… कहा िािा ह।
A. Voltage gain
B. Current gain
C. Input impedance
D. None of the above
59.
The values of h parameter of a transistor in CE arrangement are ……………… arrangement
CE वयवथिा म एक टासिथटर क h परामीटर क माि ह ……………… वयवथिा
A. The same as for CB
B. The same as for CC
C. Different from that in CB
D. None of the above
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