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.
| 151. |
In order to increase the bandwidth of tuned amplifiers, one can use:1. Tuned circuit with inductance having high Q factor2. Double tuned amplifier with two tuned circuits coupled by mutual inductance3. Staggered tuned amplifiers in which different tuned circuits which are cascaded are tuned to slightly different frequencies |
| A. | 1, 2 and 3 |
| B. | 1 and 2 only |
| C. | 2 and 3 only |
| D. | 1 and 3 only |
| Answer» D. 1 and 3 only | |
| 152. |
A transistor has / have_______ layers of material. |
| A. | 4 |
| B. | 1 |
| C. | 3 |
| D. | 2 |
| Answer» D. 2 | |
| 153. |
For the amplifier circuit shown in the given figure, which of the following statements is true? |
| A. | Vout is greater than Vin |
| B. | Vout is independent of Vin |
| C. | The circuit represents common emitter amplifier |
| D. | Vout is approximately equal to Vin |
| Answer» E. | |
| 154. |
In CB configuration of transistor, the output impedance is: |
| A. | High |
| B. | Medium |
| C. | Low |
| D. | None of the above |
| Answer» B. Medium | |
| 155. |
In the case of small BJT model with the common emitter, the collector current ic is 1.3 mA, when the collector-emitter voltage is Vce of 2.6 V. The output conductance of the circuit is |
| A. | 2.0 mΩ |
| B. | 2.0 m℧ |
| C. | 0.5 mΩ |
| D. | 0.5 m℧ |
| Answer» E. | |
| 156. |
A lateral pnp device has base width of 10 m and diffusion coefficient for base region is 10 cm2/sec. the unity gain frequency is __________. |
| A. | 20 MHz |
| B. | 10 MHz |
| C. | 6.36 MHz |
| D. | 3.18 MHz |
| Answer» E. | |
| 157. |
If an npn silicon transistor is operated at VCE = 5 V and ICE = 100 μA and has a current gain of 100 in the CE connection, then the input resistance of this circuit will be |
| A. | 250 kΩ |
| B. | 450 kΩ |
| C. | 4500 kΩ |
| D. | 25 kΩ |
| Answer» E. | |
| 158. |
A single-stage non-inverting amplifier has RF = 220 kΩ and R1 = 10k. If two such stages are cascaded, find the mid-frequency gain of the cascade. |
| A. | 27.23 dB |
| B. | 54.47 dB |
| C. | -54.47 dB |
| D. | -27.23 dB |
| Answer» C. -54.47 dB | |
| 159. |
Calculate the value of emitter current for a transistor with αdc = 0.98, ICBO = 5 μA and IB = 95 μA. |
| A. | 4.5 mA |
| B. | 4 mA |
| C. | 3.5 mA |
| D. | 5 mA |
| Answer» E. | |
| 160. |
An npn transistor (with C = 0.3 pF) has a unity gain cut off frequency fT of 4000 MHz at a dc current Ic = 1mA. The value of its Cμ (in pF) is approx. (VT = 26 V) |
| A. | 1.2 |
| B. | 30 |
| C. | 50 |
| D. | 96 |
| Answer» B. 30 | |
| 161. |
In the circuit given below, what is the operating region of the transistor, if it has a β of 100? |
| A. | Saturation |
| B. | Cutoff |
| C. | Active |
| D. | Linear |
| Answer» B. Cutoff | |
| 162. |
An amplifier has a gain of 50 dB, and noise figure of 10dB. Assuming an ambient temperature of 300 K, what will be the total equivalent noise temperature at the input of the amplifier? |
| A. | 760 K |
| B. | 360 K |
| C. | 2700 K |
| D. | 3000 K |
| Answer» D. 3000 K | |
| 163. |
In a BJT, ICO = ICBO = 2 μA. Given α = 0.99, the value of ICEO is: |
| A. | 200 μA |
| B. | 198 μA |
| C. | 2 μA |
| D. | 99 μA |
| Answer» B. 198 μA | |
| 164. |
In saturation region on transistor characteristics, collector offers: |
| A. | Low resistance |
| B. | Zero resistance |
| C. | Medium resistance |
| D. | High resistance |
| Answer» B. Zero resistance | |
| 165. |
In the circuit shown below, the voltage at each drain terminal is(i) \({V_{DD}} - \frac{{I{R_D}}}{2}\)(ii) \({V_{DD}} + \frac{{I{R_D}}}{2}\)(iii) VDD - IRD(iv) VDD + IRDChoose the correct option from the code given below:Code: |
| A. | (i) is wrong but (iv) is correct |
| B. | (ii) is correct but (iii) is wrong |
| C. | (iv) is correct but (ii) is wrong |
| D. | (iii) is correct but (i) is wrong |
| Answer» B. (ii) is correct but (iii) is wrong | |
| 166. |
In BJT the collector current is |
| A. | \(\frac{\beta }{\alpha }{I_{co}} + \beta {I_B}\) |
| B. | \(\frac{{{I_{co}}}}{{1 + \beta }} + \frac{{{I_B}}}{\beta }\) |
| C. | \(\frac{{{I_{co}}}}{{1 - a}} - \frac{{{I_B}}}{{a\;}}\) |
| D. | \(\frac{{{I_{co}}}}{{1 - \beta }} + \frac{{{I_B}}}{{a\;}}\) |
| Answer» B. \(\frac{{{I_{co}}}}{{1 + \beta }} + \frac{{{I_B}}}{\beta }\) | |
| 167. |
Following are the amplifying systems available.(a) CB transistor amplifier(b) CC transistor amplifier(c) CE transistor amplifier(d) OP AmpSequence in terms of increasing order of voltage gain. |
| A. | (b), (a), (c), (d) |
| B. | (d), (c), (a), (b) |
| C. | (a), (b), (c), (d) |
| D. | (c), (d), (b), (a) |
| Answer» B. (d), (c), (a), (b) | |
| 168. |
For a bipolar junction transistor, the common base current gain is 0.98 and the base current is 120 μA. Its common-emitter current gain will be: |
| A. | 98 |
| B. | 56 |
| C. | 49 |
| D. | 118 |
| Answer» D. 118 | |
| 169. |
Match List I with List IIList I(Configuration)List II(Equation of Base current)(a) Fixed Bias(i) \(I_B = \frac{V_{CC}-V_{BE}}{R_B+(\beta + 1)R_E}\)(b) Emitter Bias(ii) \(I_B = \frac{V_{EE}-V_{BE}}{R_B+(\beta + 1)R_E}\)(c) Emitter follower(iii) \(I_B = \frac{V_{CC}-V_{BE}}{R_B}\)(d) Common-base(iv) \(I_B = \frac{V_{EE}-V_{BE}}{R_E+(\beta + 1)}\) Choose the correct answer from the options given below: |
| A. | (a) - (ii), (b) - (iii), (c) - (i), (d) - (iv) |
| B. | (a) - (ii), (b) - (iii), (c) - (iv), (d) - (i) |
| C. | (a) - (iii), (b) - (ii), (c) - (iv), (d) - (i) |
| D. | (a) - (iii), (b) - (i), (c) - (ii), (d) - (iv) |
| Answer» E. | |
| 170. |
In the figure below you see an electronic component. Which type of electronics component is shown in the figure? |
| A. | Thyristor |
| B. | High power transistor |
| C. | Low power transistor |
| D. | Photo transistor |
| Answer» D. Photo transistor | |
| 171. |
A double-tuned circuit consisting of two magnetically coupled, identical high-Q tuned circuits (at the resonance frequency of either circuit) will have the amplitude response as: |
| A. | a peak, always |
| B. | a dip, always |
| C. | either a peak or a dip |
| D. | neither a peak nor a dip |
| Answer» B. a dip, always | |
| 172. |
For the BJT in the amplifier shown below, VBE = 0.7 V, kT/q = 26 mV. Assume that BJT output resistance (r0) is very high and the base current is negligible. The capacitors are also assumed to be short-circuited at signal frequencies. The input Vi is direct coupled. The low-frequency voltage gain v0/vi of the amplifier is |
| A. | -89.42 |
| B. | -128.21 |
| C. | -178.85 |
| D. | -256.42 |
| Answer» B. -128.21 | |
| 173. |
Improper bias of a transistor circuit leads to |
| A. | Excessive heat production in collector |
| B. | Faulty location of load line |
| C. | Heavy loading of emitter |
| D. | Distortion in output signal |
| Answer» E. | |
| 174. |
If Rs is the source resistance, the output resistance of an emitter-follower circuit using a simplified hybrid model would be |
| A. | 1/hoe |
| B. | \(\frac{{{h_{ie}} + 1/{R_S}}}{{{h_{fe}}}}\) |
| C. | RS + 1/hoe |
| D. | \(\frac{{{h_{ie}} + {R_S}}}{{1 + {h_{fe}}}}\) |
| Answer» E. | |
| 175. |
If the emitter resistance in a common-emitter voltage amplifier is not bypassed, it will |
| A. | reduce both the voltage gain and the input impedance |
| B. | reduce the voltage gain and increase the input impedance |
| C. | increase the voltage gain and reduce the input impedance |
| D. | increase both the voltage gain and the input impedance |
| Answer» C. increase the voltage gain and reduce the input impedance | |
| 176. |
Bipolar junction transistor is a __________ controlled device. |
| A. | frequency |
| B. | resistance |
| C. | current |
| D. | voltage |
| Answer» D. voltage | |
| 177. |
In a common collector amplifier the voltage gain is |
| A. | Varies with collector resistance |
| B. | Less than 1 |
| C. | Varies with input voltage. |
| D. | Varies with load resistance. |
| Answer» C. Varies with input voltage. | |
| 178. |
Operating point in a transistor amplifier circuit represents |
| A. | Values of IC and VCE when signal is applied |
| B. | Zero signal values of IC and VCE |
| C. | The magnitude of signal |
| D. | Value of IB and IC for full signal |
| Answer» C. The magnitude of signal | |
| 179. |
A two stage capacitor coupled CE amplifier has stages having a voltage gain of 100 each. It is known that the gain of each stage drops by 3 dB at lower cutoff frequency. What is the overall gain of the multistage amplifier at lower cutoff frequency? |
| A. | 74 dB |
| B. | 34 dB |
| C. | -74 dB |
| D. | -34 dB |
| Answer» B. 34 dB | |
| 180. |
A bipolar transistor is specified to have forward current gain in the range of 8 to 40. The load resistance is 11 Ω. The dc supply voltage VCC = 200 V and input voltage to the base circuit is 10 V. If VCESat = 1.0 V and VBESat = 1.5 V, what is the collector saturation current? |
| A. | 144.4 A |
| B. | 18.09 A |
| C. | 0.045 A |
| D. | 17.27 A |
| Answer» C. 0.045 A | |
| 181. |
Gama is the ratio of ____ |
| A. | emitter current to base current |
| B. | collector current to emitter current |
| C. | collector current to base current |
| D. | base current to collector current |
| Answer» B. collector current to emitter current | |
| 182. |
A bipolar junction transistor with forward current transfer ratio α = 0.98, when working in CE mode, provides current transfer ration β as |
| A. | 98 |
| B. | 0.02 |
| C. | 49 |
| D. | 0.49 |
| Answer» D. 0.49 | |
| 183. |
For a transistor used as a switch, td is delay time, tr is rise time, ts is storage time and tf is fall time. Then turn-on time tON and turn-off time tOFF are respectively |
| A. | (td + ts) and (tr + tf) |
| B. | (td + tf) and (ts + tr) |
| C. | (tr + ts) and (td + tf) |
| D. | (td + tr) and (ts + tf) |
| Answer» E. | |
| 184. |
For switching applications, a transistor needs to be biased to operate in which of the following regions? |
| A. | Inverse active region |
| B. | Active region |
| C. | Active or inverse active region |
| D. | Saturation or cut-off region |
| Answer» E. | |
| 185. |
For common-collector amplifier, the current gain (AI) is |
| A. | 1 + hfe |
| B. | \(\frac{1+h_{fe}}{1+h_{oe} R_L }\) |
| C. | \(\frac{1+h_{fe}}{1+h_{oe} h_{ie} }\) |
| D. | \(\frac{1+h_{fe}}{1+h_{ie} R_L }\) |
| Answer» C. \(\frac{1+h_{fe}}{1+h_{oe} h_{ie} }\) | |
| 186. |
PNP transistor has the following arrangement |
| A. | P type base, N type emitter, P type collector |
| B. | P type emitter, N type base, P type collector |
| C. | P type collector, N type base, P type emitter |
| D. | P type emitter, N type collector, P type base |
| Answer» C. P type collector, N type base, P type emitter | |
| 187. |
A BJT differential amplifier with matched transistors is having hfe of 200 hie of 1.2 kΩ and Rc of 3.3 kΩ. Find the differential gain, Av. |
| A. | -350 |
| B. | 300 |
| C. | -275 |
| D. | 295 |
| Answer» D. 295 | |
| 188. |
A BJT has its base current as 0.02 mA, and the current amplification factor as 0.9. Determine the value of the emitter current if the ICBO is found to be 30 μA. |
| A. | 0.9 mA |
| B. | 1 mA |
| C. | 0.5 mA |
| D. | 0.45 mA |
| Answer» D. 0.45 mA | |
| 189. |
In a BJT, if the base-emitter junction is reverse-biased and the base-collector junction is reverse-biased, it is said to operate in |
| A. | in active region |
| B. | in saturation region |
| C. | in cut-off region |
| D. | none of the above |
| Answer» D. none of the above | |
| 190. |
Emitter follower is used for: |
| A. | Current gain |
| B. | Impedance matching |
| C. | Voltage gain |
| D. | Power gain |
| Answer» C. Voltage gain | |
| 191. |
A transistor has a maximum power dissipation of 310 mW at a free air temperature of 25° C and derating factor of 2.81 mW/°C. If the transistor is to be operated at a free air temperature of 105°C, the derated power dissipation value will be |
| A. | 65.2 W |
| B. | 75.2 W |
| C. | 85.2 W |
| D. | 95.2 W |
| Answer» D. 95.2 W | |
| 192. |
A transistor is said to be useful to be configured as an amplifier when its β is |
| A. | Less than 0 |
| B. | Between 0 and 1 |
| C. | Between 1 and 50 |
| D. | > 50 |
| Answer» E. | |
| 193. |
In a circuit shown below, the base current IB is: |
| A. | 18.58 μA |
| B. | 19.73 μA |
| C. | 60.10 μA |
| D. | 2.63 μA |
| Answer» B. 19.73 μA | |
| 194. |
For normal operation of a transistor |
| A. | Forward bias the emitter diode and reverse bias the collector diode |
| B. | Forward bias the emitter diode as well as the collector diode |
| C. | Reverse bias the emitter diode as well as the collector diode |
| D. | Reverse bias the emitter diode and forward bias the collector diode |
| Answer» B. Forward bias the emitter diode as well as the collector diode | |
| 195. |
If E-B junction is reverse biased and C-B junction is forward biased, transistor is said to be in _____ |
| A. | cut-off mode |
| B. | active mode |
| C. | inverted mode |
| D. | saturation mode |
| Answer» D. saturation mode | |
| 196. |
For the base bias circuit, RB = 470 kΩ, RC = 2.2kΩ, and VCC = 18V and the transistor has an hFE of 100. Find VCE. |
| A. | 8.548 V |
| B. | 10.246 V |
| C. | 12.602 V |
| D. | 9.902 V |
| Answer» E. | |
| 197. |
For an npn BJT, the base current is 15 μA, common emitter current gain β is 100 and the base emitter voltage is 0.75 V. If reverse saturation current is negligible, its emitter current will be |
| A. | 0 mA |
| B. | 0.99 mA |
| C. | 1.5 mA |
| D. | 1.515 mA |
| Answer» E. | |
| 198. |
A microphone is connected between the base and the ground of BJT. A 1 kΩ resistance is connected between the collector and Vcc. If Is = 6 × 10-16 A and the peak value of the microphone signal is 20 mV, What is the peak value of the output signal? |
| A. | 1.29 × 10-16V |
| B. | 1.29 × 10-6V |
| C. | 1.29 × 10-12 V |
| D. | 1.29 × 10-14 V |
| Answer» D. 1.29 × 10-14 V | |
| 199. |
Match the two lists and choose the correct answer from the code given below:List IList II(a) Current gain in common base(i) 1 (ONE)(b) Input impedance in common base(ii) Less than unity(c) Voltage gain in common collector(iii) Very high ( 2 MΩ )(d) Output impedance in common base(iv) Lowest |
| A. | (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv) |
| B. | (a)-(iii), (b)-(i), (c)-(iv), (d)-(ii) |
| C. | (a)-(iv), (b)-(iii), (c)-(ii), (d)-(i) |
| D. | (a)-(ii), (b)-(iv), (c)-(i), (d)-(iii) |
| Answer» E. | |
| 200. |
At which of the following points does the transistor operate? |
| A. | Collector point |
| B. | Saturation point |
| C. | Quiescent point |
| D. | Cut-off point |
| Answer» D. Cut-off point | |