MCQOPTIONS
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MCQOPTIONS
This section includes 261 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Emitter follower is characterized by |
| A. | low output impedance and little distortion |
| B. | low output impedance and significant distortion |
| C. | significant output impedance and significant distortion |
| D. | none of these |
| Answer» B. low output impedance and significant distortion | |
| 52. |
In CE configuration, the output V-I characteristics are drawn by taking |
| A. | VCE versus IC for constant value of IE |
| B. | VCE versus IC for constant value of IB |
| C. | VCE versus IE for constant value of VCB |
| D. | None of the above |
| Answer» C. VCE versus IE for constant value of VCB | |
| 53. |
In an n-p-n transistor operating in saturated mode, the output voltage VCE is |
| A. | Greater than 2VBE |
| B. | Between 2VEB and VBE |
| C. | Less than VBE |
| D. | Equal to VBE |
| Answer» D. Equal to VBE | |
| 54. |
A signal may have frequency components which lie in the range of 0.001 Hz to 10 Hz. Which one of the following types of couplings should be chosen in a multistage amplifier designed to amplify the signal? |
| A. | Capacitor coupling |
| B. | Direct coupling |
| C. | Transformer coupling |
| D. | Double-tuned transformer coupling |
| Answer» C. Transformer coupling | |
| 55. |
For the circuit of figure sown below the value of IB is (β = 99) |
| A. | 37 μA |
| B. | 29 μA |
| C. | 40 μA |
| D. | 54 μA |
| Answer» C. 40 μA | |
| 56. |
If α = 0.98, Ico = 6 μA, & IB = 100 μA for a transistor, then the value of IC will be |
| A. | 2.3 mA |
| B. | 3.1 mA |
| C. | 4.6 mA |
| D. | 5.2 mA |
| Answer» E. | |
| 57. |
Crossover distortion occurs in ______ Amplifiers. |
| A. | Push-pull |
| B. | Class-A |
| C. | Class-B |
| D. | Class-AB |
| Answer» B. Class-A | |
| 58. |
Coupling capacitors are used in amplifier circuits to |
| A. | allow AC and DC voltages to be applied to the transistor without affecting each other |
| B. | increase coupling between the input and output AC signals |
| C. | couple the base and collector currents of the transistor |
| D. | increase the DC voltage gain |
| Answer» B. increase coupling between the input and output AC signals | |
| 59. |
Directions: The below item consists of two statements, one labelled as the 'Statement (I)' and the other as 'Statement (II)'. Examine these two statements carefully and select the answers to these items using the codes given below:Statement (I): One of the mechanisms by which a transistor's usefulness may be terminated, as the collector voltage is increased, is called punch through.Statement (II): Punch through results from the increased width of the collector-junction transition region with increased collector-junction voltage.Codes: |
| A. | Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I) |
| B. | Both Statement (I) and Statement (II) are individually true but Statement (II) is NOT the correct explanation of Statement (I) |
| C. | Statement (I) is true but Statement (II) is false |
| D. | Statement (I) is false but Statement (II) is true |
| Answer» B. Both Statement (I) and Statement (II) are individually true but Statement (II) is NOT the correct explanation of Statement (I) | |
| 60. |
Magnetic amplifiers are used for |
| A. | Voltage amplification |
| B. | Current amplification |
| C. | Power amplification |
| D. | All of these |
| Answer» C. Power amplification | |
| 61. |
A CE amplifier has a resistor RF connected between collector and base RF = 40 kΩ, RC = 4 kΩ. Given hfe = 50, rπ = 1 kΩ, the output resistance is: |
| A. | 40 kΩ |
| B. | 20 kΩ |
| C. | 4 kΩ |
| D. | 0.66 kΩ |
| Answer» D. 0.66 kΩ | |
| 62. |
In a BJT, α and β are related by the expression: |
| A. | \(\alpha = \frac{1}{{1 - \beta }}\) |
| B. | \(\alpha = \frac{1}{{1 + \beta }}\) |
| C. | \(\alpha = \frac{\beta }{{1 - \beta }}\) |
| D. | \(\alpha = \frac{\beta }{{1 + \beta }}\) |
| Answer» E. | |
| 63. |
A CE amplifier has an unbypassed emitter resistance of 0.5 kΩ and a collector load of 5 kΩ. The β of the transistor is 100 and it is operating at 1 mA. The voltage gain of the stage at mid band will be of the order of |
| A. | 200 |
| B. | 100 |
| C. | 10 |
| D. | 50 |
| Answer» B. 100 | |
| 64. |
Each transistor in the Darlington pair has hfe = 100. The overall hfe of the composite transistor, neglecting the leakage current is |
| A. | 10000 |
| B. | 10001 |
| C. | 10100 |
| D. | 10200 |
| Answer» E. | |
| 65. |
On the load line (with AC input in CE) which one of the following is NOT possible? |
| A. | cut-off point |
| B. | oscillation |
| C. | saturation point |
| D. | Q/operating point. |
| Answer» C. saturation point | |
| 66. |
For the circuit shown in the given figure, find VBB. |
| A. | 2 V |
| B. | 3 V |
| C. | 5 V |
| D. | 4 V |
| Answer» C. 5 V | |
| 67. |
Assuming VCE(Sat) = 0.3 V for a silicon transistor at an ambient temperature of 25°C and hFE = 50, then the minimum base current IB required to drive the transistor into saturation for the circuit shown is: |
| A. | 64 μA |
| B. | 78 μA |
| C. | 94 μA |
| D. | 140 μA |
| Answer» D. 140 μA | |
| 68. |
In the above circuit the optimum low frequency compensation is obtained when |
| A. | C1R1 = RECE |
| B. | C1R1 = RECC |
| C. | C1 (RC || R1) = CCRi |
| D. | C1(RC || R1) = RECE |
| Answer» D. C1(RC || R1) = RECE | |
| 69. |
For a certain transistor, if the value of Beta is equal to 500 and Base current is 5mA, then the value of Emitter current is: |
| A. | 2.5 A |
| B. | 2 A |
| C. | 3 A |
| D. | 2.505 A |
| Answer» E. | |
| 70. |
In the figure shown below, what is the expected power level at the input to the receiver? |
| A. | 20 dBm |
| B. | 30 dBm |
| C. | 40 dBm |
| D. | 50 dBm |
| Answer» C. 40 dBm | |
| 71. |
In the _____ region, a transistor act as an open switch. |
| A. | Active Region |
| B. | Saturation |
| C. | Cut-off region |
| D. | Inverse active region |
| Answer» D. Inverse active region | |
| 72. |
If the common base DC current gain of a BJT is 0.98, its common emitter DC current gain is |
| A. | 51 |
| B. | 49 |
| C. | 1 |
| D. | 0.02 |
| Answer» C. 1 | |
| 73. |
In a grounded-emitter transistor, when emitter current becomes zero in cut-of region the emitter potential is called |
| A. | Floating Emitter Potential |
| B. | Breaking Emitter Potential |
| C. | Cascading Emitter Potential |
| D. | Cut-off emitter Potential |
| Answer» B. Breaking Emitter Potential | |
| 74. |
Consider the following statements(a) BJT is a current controlled device with high input impedance and high gain band width(b) FET is a voltage- controlled device with high input impedance and low gain bandwidth(c) UJT is a negative resistance device and can be used as an oscillator(d) FET and UJT can be used for amplificationWhich of the above statements are correct |
| A. | (a) and (b) |
| B. | (b) and (c) |
| C. | (c) and (d) |
| D. | (a) and (d) |
| Answer» C. (c) and (d) | |
| 75. |
1 mW in dBm is: |
| A. | 0 dBm |
| B. | -30 dBm |
| C. | 30 dBm |
| D. | 1 dBm |
| Answer» B. -30 dBm | |
| 76. |
A transistor can be made to operate as a switch by operating it in which of the following regions? |
| A. | Active region |
| B. | active region, cut-off region |
| C. | Active region, saturation region |
| D. | Saturation region, cut-off region |
| Answer» E. | |
| 77. |
For a certain transistor, β = 50. Find the value of α. |
| A. | 0.88 |
| B. | 0.98 |
| C. | 0.78 |
| D. | 0.68 |
| Answer» C. 0.78 | |
| 78. |
In the transistor circuit shown below, the collector to ground voltage is + 20 V.The possible condition is |
| A. | Collector-emitter terminals shorted |
| B. | emitter to ground connection open |
| C. | 10 kΩ resistor open |
| D. | collector-base terminals shorted |
| Answer» C. 10 kΩ resistor open | |
| 79. |
For the common emitter amplifier circuit given below what is the quiescent collector current? Assume that base current is negligible and VBE = 0.7 V |
| A. | o mA |
| B. | 4 mA |
| C. | 7.5 mA |
| D. | 10 mA |
| Answer» C. 7.5 mA | |
| 80. |
Compared to a common base and common collector, the common emitter transistor circuit has |
| A. | high power gain |
| B. | high current gain |
| C. | high voltage gain |
| D. | low current gain |
| Answer» B. high current gain | |
| 81. |
In a Bipolar Junction Transistor (BJT) due to current flow to small portion of the base, hot spots are produced causing localized excessive heating and damaging the transistor. This switching limit is called |
| A. | Forward-Biased Safe Operating Area (FBSOA) |
| B. | Reverse-Biased Safe Operating Area (RBSOA) |
| C. | Power Derating |
| D. | Second Breakdown (SB) |
| Answer» E. | |
| 82. |
In the common-base configuration, the collector current is given by: |
| A. | \({I_C} = \frac{\alpha }{{1 + \alpha }}{I_B} + \frac{1}{{1 - \alpha }}{I_{CBO}}\) |
| B. | \({I_C} = \frac{\alpha }{{1 - \alpha }}{I_B} + \frac{1}{{1 + \alpha }}{I_{CBO}}\) |
| C. | \({I_C} = \frac{\alpha }{{1 + \alpha }}{I_B} + \frac{1}{{1 + \alpha }}{I_{CBO}}\) |
| D. | \({I_C} = \frac{\alpha }{{1 - \alpha }}{I_B} + \frac{1}{{1 - \alpha }}{I_{CBO}}\) |
| Answer» E. | |
| 83. |
A single-stage amplifier has a voltage gain of 100. The load connected to the collector is 500 Ω and its input impedance is 1 kΩ. Two such stages are connected in cascade through an R-C coupling. The overall gain is |
| A. | 10000 |
| B. | 6666.66 |
| C. | 5000 |
| D. | 1666.66 |
| Answer» C. 5000 | |
| 84. |
Linear amplifier with a gain of 30 dB is fed with 1.0 μW power. The output power of the amplifier |
| A. | 1.0 W |
| B. | 0 dBm |
| C. | 30 dBm |
| D. | -30 dBm |
| Answer» C. 30 dBm | |
| 85. |
A CE amplifier has RL = 10 KΩ. Given that hie = 1 KΩ, hfe = 50, hre = 0 and 1/hoe = 40 KΩ. Calculate the voltage gain. |
| A. | -500 |
| B. | -400 |
| C. | 40 |
| D. | 50 |
| Answer» C. 40 | |
| 86. |
Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R)Assertion (A): The circuits that are quite stable and relatively insensitive to temperature variation have high stability factors.Reasons (R): For a particular configuration, if a change in ICO fails to produce a significant change in IC, the stability factor will be quite small.In the light of the above statement, choose the correct answer from the options given below:(1) Both (A) and (R) are true and (R) is the correct explanation of (A)(2) Both (A) and (R) are true but (R) is not the correct explanation of (A)(3) (A) is true but (R) is false(4) (A) is false but (R) is true |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» E. | |
| 87. |
Given figure shows a silicon transistor connected as a common emitter amplifier. The quiescent collector voltage of the circuit is approximately. |
| A. | 20/3 V |
| B. | 10 V |
| C. | 14 V |
| D. | 20 V |
| Answer» D. 20 V | |
| 88. |
A Darlington emitter follower circuit is sometimes used in the output stage of TTL gate to _____. |
| A. | To decrease power consumption |
| B. | Decrease its IOH |
| C. | Increase its IOL |
| D. | To increase speed |
| Answer» E. | |
| 89. |
If biasing is not done in an amplifier circuit, it results in |
| A. | a decrease in the base current |
| B. | Excessive collector bias |
| C. | Unfaithful amplification |
| D. | High power loss |
| Answer» D. High power loss | |
| 90. |
Arrange the following amplifier in the increasing order of their Current Gain.(a) Common-emitter amplifier(b) Common-base amplifier(c) Darlington amplifier in common-emitter configuration(d) Common-collector amplifier |
| A. | (b), (a), (d), (c) |
| B. | (a), (b), (c), (d) |
| C. | (c), (d), (a), (b) |
| D. | (d), (c), (b), (a) |
| Answer» B. (a), (b), (c), (d) | |
| 91. |
n-p-n transistors are preferred over p-n-p transistors because they have |
| A. | high mobility of holes |
| B. | equal to mobility of holes |
| C. | low mobility of holes |
| D. | higher mobility of electrons than the mobility of holes in p-n-p transistors |
| Answer» E. | |
| 92. |
Direction: Question consists of two statements, one labeled as the 'Assertion (A)' and the other as 'Reason (R)'. Examine these two statements carefully and select the answer to this question using the codes given below:Assertion (A): A bipolar junction transistor is basically a current amplifier.Reason (R): The most simplified model of a BJT has a current-dependent current source in its output circuit, whose magnitude directly depends upon the input current. |
| A. | Both A and R are individually true and R is the correct explanation of A |
| B. | Both A and R are individually true but R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are individually true but R is not the correct explanation of A | |
| 93. |
In an RC coupled transistor amplifier1. Low-frequency response is determined by coupling capacitors.2. High-frequency response is determined by junction capacitances.3. Mid-frequency response is determined by both coupling and junction capacitances. |
| A. | 1 and 2 only |
| B. | 1 and 3 only |
| C. | 2 and 3 only |
| D. | 1, 2 and 3 |
| Answer» B. 1 and 3 only | |
| 94. |
Consider the common-collector amplifier in the figure (bias circuitry ensures that the transistor operates in forward active region, but has been omitted for simplicity). Let IC be the collector current, VBE be the base-emitter voltage and VT by the thermal voltage. Also, |
| A. | gm RE ≪ 1 |
| B. | ICRE VT |
| C. | gmr0 1 |
| D. | VBE VT |
| Answer» C. gmr0 1 | |
| 95. |
How many cascaded stages of CE amplifiers will result in polarity inversion of the input signal? |
| A. | Two |
| B. | Three |
| C. | Four |
| D. | None |
| Answer» C. Four | |
| 96. |
An amplifier should have |
| A. | High fidelity |
| B. | Low noise |
| C. | Stable operation |
| D. | All of the above |
| Answer» E. | |
| 97. |
Find the approximate collector current in the given transistor circuit. (Take current gain, β = 100) |
| A. | 10 mA |
| B. | 1.25 mA |
| C. | 1 mA |
| D. | 11.5 mA |
| Answer» D. 11.5 mA | |
| 98. |
h - parameters of a transistor |
| A. | Are constant |
| B. | Vary with temperature |
| C. | Are dependent upon collector current |
| D. | None of the above |
| Answer» C. Are dependent upon collector current | |
| 99. |
Darlington pairs are frequently used in linear ICs because they |
| A. | Do not require any capacitor or inductors |
| B. | Have enormous impedance transformation capability |
| C. | Can be readily formed/hooked from two adjacent transistors |
| D. | Resemble emitter follower |
| Answer» C. Can be readily formed/hooked from two adjacent transistors | |
| 100. |
Among these which one is correct about the characteristics of common collector transistor? |
| A. | It has a very low input impedance |
| B. | It has zero input impedance |
| C. | It has a high input impedance |
| D. | It has a low input impedance |
| Answer» D. It has a low input impedance | |