All STD 12 - Semicondutor electronics questions
Newest firstShowing 51–100 of 181 questions
- 51. A zener diode of power rating \(1.6\,W\) is to be used as voltage regulator. If the zener diode has a breakdown of \(8\,V\) and it has to regulate voltage fluctuating between \(3\,V\) and \(10 \,V\). The value of resistance \(R_5\) for safe operation of diode will be \(.........\Omega\)
2023 Medium - 52. For a given transistor amplifier circuit in \(CE\) configuration \(V_{C C}=1 V , R_c=1 k \Omega, R_b=100 k \Omega\) and \(\beta=100\). Value of base current \(I_b\) is
2023 Medium - 53. From the given transfer characteristic of a transistor in \(CE\) configuration, the value of power gain of this configuration is \(10^{ x }\), for \(R_B=10\,k \Omega\), and \(R _C=1\,k \Omega\). The value of \(x\) is \(.....\).
2023 Hard - 54. Given below are two statements : one is labeled as Assertion \(A\) and the other is labeled as Reason \(R\) Assertion \(A:\) Photodiodes are used in forward bias usually for measuring the light intensity. Reason \(R:\) For a \(p-n\) junction diode, at applied voltage \(V\) the current in the forward bias is more than the current in the reverse bias for \(\left|V_z\right| > \pm V \geq\left|V_0\right|\) where \(V_0\) is the threshold voltage and \(V _{ z }\) is the breakdown voltage. In the light of the above statements, choose the correct answer from the options given below 2023 Medium
- 55. Given below are two statements : one is labelled as Assertion \(A\) and the other is labelled as Reason \(R\) Assertion \(A :\) Photodiodes are preferably operated in reverse bias condition for light intensity measurement. Reason \(R\) : The current in the forward bias is more than the current in the reverse bias for a \(p - n\) junction diode. In the light of the above statement, choose the correct answer from the options given below : 2023 Medium
- 56. Given below are two statements: one is labelled as Assertion \(A\) and the other is labelled as Reason \(R\) Assertion \(A:\) Diffusion current in a \(p-n\) junction is greater than the drift current in magnitude if the junction is forward biased. Reason \(R:\) Diffusion current in a \(p-n\) junction is from the \(n\)-side to the \(p\)-side if the junction is forward biased. In the light of the above statements, choose the most appropriate answer from the options given below 2023 Medium
- 57. If each diode has a forward bias resistance of \(25\,\Omega\) in the below circuit,Which of the following options is correct:
2023 Medium - 58. In an \(n-p-n\) common emitter (\(CE\)) transistor the collector current changes from \(5\,mA\) to \(16\,mA\) for the change in base current from \(100\,\mu A\) and \(200\,\mu A\), respectively. The current gain of transistor is 2023 Easy
- 59. In the given circuit, the current \((I)\) through the battery will be \(..........\,A\)
2023 Medium - 60. Match the List \(I\) with List \(II\)
Choose the correct answer from the options given below: 2023 MediumLIST \(I\) LIST \(II\) \(A\) Intrinsic Semiconductor \(I\) Fermi-level near conduction band \(B\) \(n-\)type semiconductor \(II\) Fermi-level at middle \(C\) \(p-\) type semiconductor \(III\) Fermi-level near valence band \(D\) Metals \(IV\) Fermi-level inside conduction band - 61. Name the logic gate equivalent to the diagram attached
2023 Medium - 62. Statement \(I :\) When a Si sample is doped with Boron, it becomes \(P\) type and when doped by Arsenic it becomes \(N-\)type semi conductor such that \(P-\)type has excess holes and N-type has excess electrons. Statement \(II\) : When such \(P-\)type and \(N-\)type semi-conductors, are fused to make a junction, a current will automatically flow which can be detected with an externally connected ammeter. In the light of above statements, choose the most appropriate answer from the options given below. 2023 Medium
- 63. The effect of increase in temperature on the number of electrons in conduction band \(\left( n _{ e }\right)\) and resistance of a semiconductor will be as: 2023 Medium
- 64. The logic gate equivalent to the given circuit diagram is:
2023 Medium - 65. The logic operations performed by the given digital circuit is equivalent to:
2023 Medium - 66. Which of the following statement is not correct in the case of light emitting diodes? \(A.\) It is a heavily doped p-n junction. \(B.\) It emits light only when it is forward biased. \(C.\) It emits light only when it is reverse biased. \(D.\) The energy of the light emitted is equal to or slightly less than the energy gap of the semiconductor used. Choose the correct answer from the options given below : 2023 Medium
- 67. A logic gate circuit has two inputs \(A\) and \(B\) and output \(Y\). The voltage waveforms of \(A, B\) and \(Y\) are shown below The logic gate circuit is.
2022 Medium - 68. A potential barrier of \(0.4 \,V\) exists across a p-n junction. An electron enters the junction from the \(n\)-side with a speed of \(6.0 \times 10^{5} \,ms ^{-1}\). The speed with which electron enters the \(p\) side will be \(\frac{x}{3} \times 10^{5} \,ms ^{-1}\) the value of \(x\) is .............. (Given mass of electron \(=9 \times 10^{-31} \,kg\), charge on electron \(=1.6 \times 10^{-19} \,C\).) 2022 Hard
- 69. A transistor is used in an amplifier circuit in common emitter mode. If the base current changes by \(100 \,\mu A\), it brings a change of \(10 \,mA\) in collector current. If the load resistance is \(2 \,k \Omega\) and input resistance is \(1 \,k \Omega\), the value of power gain is \(x \times 10^{4}\). The value of \(x\) is_________ 2022 Medium
- 70. A transistor is used in common-emitter mode in an amplifier circuit. When a signal of \(10\, mV\) is added to the base-emitter voltage, the base current changes by \(10 \mu A\) and the collector current changes by \(1.5 \,mA\). The load resistance is \(5 \,k \Omega\). The voltage gain of the transistor will be 2022 Medium
- 71. A Zener of breakdown voltage \(V_{z}=8\,V\) and maximum zener current, \(I _{ ZM }=10\,mA\) is subjected to an input voltage \(V _{ i }=10\,V\) with series resistance \(R=100\,\Omega\). In the given circuit \(R_{L}\) represents the variable load resistance. The ratio of maximum and minimum value of \(R_{L}\) is
2022 Hard - 72. An \(n.p.n\) transistor with current gain \(\beta=100\) in common emitter configuration is shown in figure. The output voltage of the amplifier will be\(.....V\)
2022 Medium - 73. As per the given circuit, the value of current through the battery will be \(\dots \; A\).
2022 Medium - 74. For a constant collector-emitter voltage of \(8\,V\), the collector current of a transistor reached to the value of \(6\,mA\) from \(4\,mA\), whereas base current changed from \(20\,\mu A\) to \(25\,\mu\,A\) value. If transistor is in active state, small signal current gain (current amplification factor) will be. 2022 Medium
- 75. For a transistor to act as a switch, it must be operated in 2022 Medium
- 76. For using a multimeter to identify diode from electrical components. choose the correct statement out of the following about the diode 2022 Medium
- 77. Given below are two statements : One is labelled as Assertion \(A\) and the other is labelled as Reason \(R\). Assertion \(A\) : \(n - p - n\) transistor permits more current than a \(p-n-p\) transistor Reason \(R\) : Electrons have greater mobility as a charge carrier Choose the correct answer from the options given below 2022 Medium
- 78. Identify the logic operation performed by the given circuit
2022 Medium - 79. If the potential barrier across a \(p - n\) junction is \(0.6\,V\). Then the electric field intensity, in the depletion region having the width of \(6 \times 10^{-6} m\), will be \(......\times 10^{5} N / C\). 2022 Easy
- 80. In an experiment of \(CE\) configuration of \(n-p-n\) transistor, the transfer characteristics are observed as given in figure. If the input resistance is \(200 \Omega\) and output resistance is \(60 \Omega\) the voltage gain in this experiment will be..........
2022 Medium - 81. In the circuit shown below, maximum zener diode current will be \(.....mA\)
2022 Medium - 82. In the circuit, the logical value of \(A =1\) or \(B =1\) when potential at \(A\) or \(B\) is \(5\,V\) and the logical value of \(A=0\) or \(B=0\) when potential at \(A\) or \(B\) is \(0\,V\). The truth table of the given circuit will be :
2022 Hard - 83. In the following circuit, the correct relation between output \(( Y )\) and inputs \(A\) and \(B\) will be
2022 Hard - 84. In the given circuit- the value of current \(I _{ L }\) will be \(mA\). (When \(R _{ L }=1 \,k\, \Omega\) )
2022 Easy - 85. The cut-off voltage of the diodes (shown in figure) in forward bias is \(0.6 \,V\). The current through the resister of \(40 \,\Omega\) is ........... \(mA\).
2022 Medium - 86. The energy band gap of semiconducting material to produce violet (wavelength \(=4000 \,A^{\circ}\) ) LED is \(.......eV\). (Round off to the nearest integer). 2022 Easy
- 87. The \(I-V\) characteristics of a \(p - n\) junction diode in forward bias is shown in the figure. The ratio of dynamic resistance, corresponding to forward bias voltages of \(2 \; V\) and \(4 \; V\) respectively, is
2022 Medium - 88. The photodiode is used to detect the optiocal signals. These diodes are preferably operated in reverse biased mode because. 2022 Medium
- 89. The positive feedback is required by an amplifier to act an oscillator. The feedback here means ........... 2022 Medium
- 90. The typical transfer characteristic of a transistor in \(CE\) configuration is shown in figure. A load resistor of \(2\,k\Omega\) is connected in the collector branch of the circuit used. The input resistance of the transistor is \(0.50\,k \Omega\). The voltage gain of the transistor is.
2022 Hard - 91. Two ideal diodes are connected in the network as shown in figure. The equivalent resistance between \(A\) and \(B\) is \(.......\Omega\).
2022 Medium - 92. A \(5 \,V\) battery is connected across the points \(X\) and \(Y\). Assume \(D_{1}\) and \(D_{2}\) to be normal silicon diodes. Find the current (in \(A\)) supplied by the battery if the \(+ve\) terminal of the battery is connected to point \(X\)
2021 Medium - 93. A circuit is arranged as shown in figure. The output voltage \({V}_{0}\) is equal to \(\ldots \ldots . {V}\).
2021 Hard - 94. A common transistor radio set requires \(12\,V (D.C.)\) for its operation. The \(D.C.\) source is constructed by using a transformer and a rectifier circuit, which are operated at \(220\, V\) \((A.C.)\) on standard domestic \(A.C.\) supply. The number of turns of secondary coil are \(24,\) then the number of turns of primary are 2021 Medium
- 95. A trransistor is connected in common emitter circuit configuration, the collector supply voltage is \(10 \,{V}\) and the voltage drop across a resistor of \(1000\, \Omega\) in the collector circuit is \(0.6\, {V}\). If the current gain factor \((\beta)\) is \(24\) , then the base currect is \(....\,\mu\) \(A.\) (Round off to the Nearest Integer) 2021 Hard
- 96. A zener diode having zener voltage \(8\, {V}\) and power dissipation rating of \(0.5\, {W}\) is connected across a potential divide arranged with maximum potential drop across zener diode is as shown in the diagram. The value of protective resistance \({R}_{{p}}\) is \(....\,\Omega\)
2021 Medium - 97. A zener diode of power rating \(2\, {W}\) is to be used as a voltage regulator. If the zener diode has a breakdown of \(10 \,{V}\) and it has to regulate voltage fluctuated between \(6\, {V}\) and \(14\, {V}\), the value of \({R}_{{s}}\) for safe operation should be \(....\Omega\)
2021 Hard - 98. An \(npn\) transistor operates as a common emitter amplifier with a power gain of \(10^{6} .\) The input circuit resistance is \(100\, \Omega\) and the output load resistance is \(10\, K \Omega\). The common emitter current gain ' \(\beta\) ' will be............. (Round off to the Nearest Integer) 2021 Medium
- 99. Consider a situation in which reverse biased current of a particular \(P-N\) junction increases when it is exposed to a light of wavelength \(\le 621\, {nm}\). During this process, enhancement in carrier concentration takes place due to generation of hole-electron pairs. The value of band gap is nearly. (In \({eV}\)) 2021 Medium
- 100. Find the truth table for the function \(Y\) and \(A\) and \(B\) represented in the following figure.
2021 Medium
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