MCQOPTIONS
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MCQOPTIONS
This section includes 2171 Mcqs, each offering curated multiple-choice questions to sharpen your ENGINEERING SERVICES EXAMINATION (ESE) knowledge and support exam preparation. Choose a topic below to get started.
| 1201. |
In a two stage CE amplifier circuit, the ac collector resistance of the first stage depends on |
| A. | load resistance |
| B. | input impedance of first stage |
| C. | input impedance of second stage |
| D. | all of the above |
| Answer» D. all of the above | |
| 1202. |
A three terminal monolithic IC regulator can be used as |
| A. | an a adjustable output voltage regulator alone |
| B. | an adjustable output voltage regulator & a current regulator |
| C. | a current regulator & a power switch |
| D. | a current regulator alone |
| Answer» E. | |
| 1203. |
In order to obtain triangular pulses at the output of the circuit in the figure, the input should be. |
| A. | grounded |
| B. | a square wave |
| C. | Triangular wave |
| D. | Trigger |
| Answer» B. a square wave | |
| 1204. |
Which of the following parameters of CE circuit has the unit of ohms? |
| A. | hie |
| B. | hre |
| C. | hfe |
| D. | hoe |
| Answer» B. hre | |
| 1205. |
When the emitter current of a transistor is changed by 1 mA, its collector current changes by 0.990 mA. The common-emitter short-circuit current gain is |
| A. | 1 |
| B. | 199 |
| C. | 99 |
| D. | 9.9 |
| Answer» D. 9.9 | |
| 1206. |
In figure which diode will conduct and what will be the value of V0? |
| A. | D3, 1 V |
| B. | D1, 2 V |
| C. | D2, 5 V |
| D. | D1, 5 V |
| Answer» D. D1, 5 V | |
| 1207. |
Which of the following contributes to harmonics distortion in amplifiers? |
| A. | Positive feedback |
| B. | Presence of noise |
| C. | Defective active device |
| D. | Non-linearity in active device |
| Answer» E. | |
| 1208. |
Two CE stages, 1 and 2 are coupled through a capacitor. VCC is the same for both. Base resistances RB1 and RB2 are such that RB1 > RB2. Then |
| A. | base currents for both stages are equal |
| B. | base current of stage 1 is more than that of stage 2 |
| C. | base current of stage 2 is more than that of stage 1 |
| D. | either (b) or (c) |
| Answer» D. either (b) or (c) | |
| 1209. |
Assertion (A): CE amplifier is the most widely used BJT amplifierReason (R): CE amplifier has zero phase difference between input and output |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» D. A is wrong R is correct | |
| 1210. |
CMOS is widely used in |
| A. | digital wrist watches |
| B. | analog circuits |
| C. | high power circuits |
| D. | all of the above |
| Answer» B. analog circuits | |
| 1211. |
Find the odd one out |
| A. | sweep voltage generator |
| B. | multivibrators |
| C. | sine wave oscillators |
| D. | blocking oscillators |
| Answer» D. blocking oscillators | |
| 1212. |
The ideal op-amp has the following characteristics |
| A. | Ri = ∞, A = ∞, R0 = 0 |
| B. | Ri = 0, A = ∞, R0 = 0 |
| C. | Ri = ∞, A = 0, R0 = 0 |
| D. | Ri = 0, A = ∞, R0 = ∞ |
| Answer» B. Ri = 0, A = ∞, R0 = 0 | |
| 1213. |
In operational Amplifier, Common mode voltage gain should be |
| A. | 0 |
| B. | ∞ |
| C. | 1 |
| D. | 0.5 |
| Answer» B. ∞ | |
| 1214. |
In a transistor, current ICBO flow when |
| A. | some D.C. voltage is applied in the reverse direction to the emitter junction with the collector open circuit |
| B. | some D.C. voltage is applied in the forward direction to the collector junction with the emitter open circuit |
| C. | some D.C. voltage is applied in the reverse direction to the collector junction with the emitter open circuited |
| D. | some D.C. voltage is applied in the forward direction to the emitter junction with the collector open circuited |
| Answer» D. some D.C. voltage is applied in the forward direction to the emitter junction with the collector open circuited | |
| 1215. |
A class B amplifier1. is biased just at cutoff2. has a high theoretical efficiency of 78.5% because its quiescent current is low3. is biased at midpoint of load line Of the above statements |
| A. | 2 and 3 are correct |
| B. | 1 alone is correct |
| C. | 1 and 2 are correct |
| D. | 2 alone is correct |
| Answer» E. | |
| 1216. |
The main application of enhancement mode MOSFET is in |
| A. | amplifier circuits |
| B. | oscillator circuits |
| C. | switching circuits |
| D. | all of the above |
| Answer» D. all of the above | |
| 1217. |
If input frequency is 50 Hz, the frequency of output wave in a half wave diode rectifier circuit is |
| A. | 25 Hz |
| B. | 50 Hz |
| C. | 100 Hz |
| D. | 200 Hz |
| Answer» C. 100 Hz | |
| 1218. |
A full wave rectifier using centre tapped transformer and a bridge rectifier use similar diodes and have equal no load output voltage. Under equal load conditions |
| A. | Output voltage of bridge rectifier |
| B. | Output voltage of bridge rectifier will be more than that of other |
| C. | Output voltage of both will be exactly equal |
| D. | Output voltage of any one may be more than that of other |
| Answer» B. Output voltage of bridge rectifier will be more than that of other | |
| 1219. |
To draw dc equivalent circuit for a CE amplifier circuit we should |
| A. | Reduce all ac sources to zero |
| B. | Open all capacitors |
| C. | Reduce all ac sources to zero and open all capacitors |
| D. | Reduce all ac sources to zero and short all capacitors |
| Answer» D. Reduce all ac sources to zero and short all capacitors | |
| 1220. |
A two stage amplifier has an upper cutoff frequency of 2 MHz and a lower cutoff frequency of 2 MHz and a lower cut off frequency of 30 Hz. If both stages are similar, their individual upper and lower cut off frequencies respectively are |
| A. | 4 MHz and 60 MHz |
| B. | 3 MHz and 20 Hz |
| C. | 3 MHz and 60 Hz |
| D. | 4 MHz and 20 Hz |
| Answer» C. 3 MHz and 60 Hz | |
| 1221. |
In a shunt-shunt negative feedback amplifier, as compared to the basic amplifier |
| A. | both input and output impedances, decrease |
| B. | input impedance decreases but output impedance increase |
| C. | I/P impedance increases but O/P impedance decreases |
| D. | both input and O/P impedance increases |
| Answer» C. I/P impedance increases but O/P impedance decreases | |
| 1222. |
The Clapp oscillator shown in figure will operate at |
| A. | 4.6 kHz |
| B. | 46 kHz |
| C. | 460 kHz |
| D. | 4600 kHz |
| Answer» D. 4600 kHz | |
| 1223. |
In figure, secondary winding has 40 turns. For maximum power transformer to 2 ohm resistance the number of turns in primary is |
| A. | 20 |
| B. | 40 |
| C. | 80 |
| D. | 160 |
| Answer» D. 160 | |
| 1224. |
In a negative feedback amplifier A = 100, β = 0.04 and Vs = 50 mV, then feedback will be |
| A. | 4 |
| B. | 8 |
| C. | 10 |
| D. | 2 |
| Answer» B. 8 | |
| 1225. |
The most widely used LC oscillator is |
| A. | Hartley oscillator |
| B. | Crystal oscillator |
| C. | Colpitt's oscillator |
| D. | Clapp's oscillator |
| Answer» B. Crystal oscillator | |
| 1226. |
In an oscillator the total phase shift around the loop must be |
| A. | 180° |
| B. | 90° |
| C. | 270° |
| D. | 0° |
| Answer» E. | |
| 1227. |
The circuit of the figure is an example of feedback of the following type |
| A. | current series |
| B. | current shunt |
| C. | voltage series |
| D. | voltage shunt |
| Answer» E. | |
| 1228. |
The input impedance of a non-inverting amplifier is very low. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» C. May be True or False | |
| 1229. |
As compared to a full wave diode rectifier circuit using centre tapped transformer, the bridge diode rectifier circuit has the main advantage of |
| A. | higher current carrying capacity |
| B. | higher efficiency |
| C. | lower ripple factor |
| D. | lower PIV |
| Answer» E. | |
| 1230. |
Overall efficiency of class B amplifier is |
| A. | 72% |
| B. | 75% |
| C. | 78.5% |
| D. | 70% |
| Answer» D. 70% | |
| 1231. |
A typical value of gm for a FET is about 25 μs. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» C. May be True or False | |
| 1232. |
Negative feedback in amplifier |
| A. | reduces gain |
| B. | increases frequency and phase distortion |
| C. | reduces bandwidth |
| D. | increases noise |
| Answer» B. increases frequency and phase distortion | |
| 1233. |
Which of the following number specification refers to FET with one gate? |
| A. | 2N |
| B. | 3N |
| C. | 3Y |
| D. | 3X |
| Answer» C. 3Y | |
| 1234. |
In figure output impedance of amplifier is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 1235. |
A voltage multiplier circuit, using diodes and capacitors is suitable for |
| A. | high voltage high current device |
| B. | high voltage low current device |
| C. | low voltage low current device |
| D. | low voltage high current device |
| Answer» C. low voltage low current device | |
| 1236. |
In common base amplifier the current gain is less than one, but the voltage gain may be anywhere from |
| A. | 0.5 to 1 |
| B. | 1 to 5 |
| C. | 5 to 10 |
| D. | 50 to 2000 |
| Answer» E. | |
| 1237. |
A class C amplifier uses |
| A. | high Q tuned circuit |
| B. | low Q tuned circuit |
| C. | untuned circuit |
| D. | either (b) or (c) |
| Answer» B. low Q tuned circuit | |
| 1238. |
Higher order active filters are used for variable |
| A. | bandwidth |
| B. | gain in the pass band |
| C. | impedance |
| D. | roll off rate |
| Answer» E. | |
| 1239. |
The maximum efficiency of class A amplifier is |
| A. | 100% |
| B. | 81.8% |
| C. | 50% |
| D. | 40% |
| Answer» D. 40% | |
| 1240. |
In figure the coordinates of Q point on the load line are (Neglect VBE) |
| A. | IC = 10 mA, VCE = 15 V |
| B. | IC = 5 mA, VCE = 22.5 V |
| C. | IC = 5 mA, VCE = 15 V |
| D. | IC = 10 mA, VCE = 22.5 V |
| Answer» B. IC = 5 mA, VCE = 22.5 V | |
| 1241. |
A transistor with α = 0.98 then β will be |
| A. | 49 |
| B. | 50 |
| C. | 47 |
| D. | 48 |
| Answer» B. 50 | |
| 1242. |
The current ICBO flows in |
| A. | base and emitter leads |
| B. | base and collector leads |
| C. | collector and emitter leads |
| D. | collector, emitter and base leads |
| Answer» C. collector and emitter leads | |
| 1243. |
In the self biasing scheme (RF across collector to base) of BJT, S1 tends to unity by __________ RC is the collector load Resistance. |
| A. | increasing RF |
| B. | decreasing RF |
| C. | decreasing RF and increasing RC |
| D. | increasing RF and decreasing RC |
| Answer» D. increasing RF and decreasing RC | |
| 1244. |
A JFET can operate on |
| A. | enhancement mode only |
| B. | depletion mode only |
| C. | both depletion as well as enhancement modes |
| D. | neither depletion nor enhancement mode |
| Answer» C. both depletion as well as enhancement modes | |
| 1245. |
In a series regulated power supply circuit the voltage gain of pass transistor satisfies the condition |
| A. | Av → ∞ |
| B. | 1 << Av → ∞ |
| C. | Av ≈ 1 |
| D. | Av << 1 |
| Answer» D. Av << 1 | |
| 1246. |
Values of VT at 20°C for an ideal P-N diode |
| A. | 25.27 mV |
| B. | 30.3 mV |
| C. | 23 mV |
| D. | 50 mV |
| Answer» B. 30.3 mV | |
| 1247. |
The most commonly used bias in BJT amplifier circuits is |
| A. | voltage divider bias |
| B. | emitter bias |
| C. | collector bias |
| D. | collector feedback bias |
| Answer» B. emitter bias | |
| 1248. |
In every practical oscillator the loop gain is slightly more than unit and amplitude of oscillations is limited by |
| A. | magnitude of loop gain |
| B. | onset of non-linearity |
| C. | magnitude of gain |
| D. | β |
| Answer» C. magnitude of gain | |
| 1249. |
The RC network of wein bridge oscillator consists of resistors and capacitors of values R = 220 kΩ and C = 250 PF Determine the frequency of oscillation |
| A. | 2.98 kHz |
| B. | 3 kHz |
| C. | 2 kHz |
| D. | 10 kHz |
| Answer» B. 3 kHz | |
| 1250. |
A transistor amplifier has poles ats1 = - 0.000245 x 10⁹ rad/sec.s2 = - 0.0748 x 10⁹ rad/sec.s3 = - 0.670 x 10⁹ rad/sec.s4 = - 4.38 x 10⁹ rad/sec.The upper 3 dB frequency of the amplifier will be |
| A. | s1 |
| B. | s1 + s2 + s3 + s4 |
| C. | s1 + s4 |
| D. | s4 |
| Answer» B. s1 + s2 + s3 + s4 | |