MCQOPTIONS
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MCQOPTIONS
This section includes 905 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics & Communication Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
The VTH at terminals A and B is equal to, |
| A. | 0 V |
| B. | 5 V |
| C. | - 5 V |
| D. | None of these |
| Answer» C. - 5 V | |
| 152. |
The number of variables in a function is odd and the number of minterms with even number of 0's are same as the number of minterms with odd number at 1 's, the expression formed can be represented in __________ as well as __________ form. |
| A. | exclusive - OR, NOR |
| B. | equivalence, exclusive - OR |
| C. | AND, coincidence |
| D. | OR, exclusive - OR |
| Answer» C. AND, coincidence | |
| 153. |
In the epitaxial diffused method of fabricating integrating circuits the process involved are __________ Epitaxial growthDiffusionSilicon diode growthVacuum evaporation of aluminiumPhotoetching The correct order is |
| A. | 1 - 2 - 3 - 4 - 5 |
| B. | 1 - 3 - 5 - 2 - 4 |
| C. | 3 - 1 - 4 - 5 - 2 |
| D. | 1 - 3 - 2 - 4 - 5 |
| Answer» C. 3 - 1 - 4 - 5 - 2 | |
| 154. |
A silicon PN junction with no bias have a doping concentration of Nd = 2 x 1016 cm-3 and Na = 1016 cm-3. The space charge width is: |
| A. | 3.345 x 10-3 cm |
| B. | 3.345 x 10-4 cm |
| C. | 3.345 x 10-5 cm |
| D. | 3.345 x 10-6 cm |
| Answer» D. 3.345 x 10-6 cm | |
| 155. |
V(t) across R2 for t > 0 is given by, |
| A. | 2 - 2e-2t |
| B. | 2 - e-2t |
| C. | 2 - e-t |
| D. | 1 - e-t |
| Answer» C. 2 - e-t | |
| 156. |
The internal resistance of a current source used in the model of a BJT while analyzing a circuit using BJT is : |
| A. | very high |
| B. | very low |
| C. | zero |
| D. | of the order of a few mega ohms |
| Answer» B. very low | |
| 157. |
Consider the signal S(t) shown below :The slope of the matched filter output during the interval |
| A. | 8 |
| B. | 12 |
| C. | 16 |
| D. | 18 |
| Answer» B. 12 | |
| 158. |
50 independent low pass signals of bandwidth W, 2W, 3W, W, 2W, 3W, W, 2W, 3W Hz are to be time division multiplexer on a common channel using PAM. To achieve this, the minimum transmission capacity of the channel should be __________ . |
| A. | 1 Hz |
| B. | 12 Hz |
| C. | 3 Hz |
| D. | 6 Hz |
| Answer» C. 3 Hz | |
| 159. |
For good quality signal transmission all frequency components should have the same transmission delay, td and same phase shift-Φs. What can be said about the statement? |
| A. | Correct |
| B. | True from td but not for Φs |
| C. | Not true for td but true for Φs |
| D. | Both td and Φs are not involved in quality |
| Answer» E. | |
| 160. |
A divide by 78 counters can be realized by using |
| A. | six mod-13 counters |
| B. | thirteen mod-6 counters |
| C. | one mod 13 counter followed by one mod-6 counter |
| D. | thirteen mod-13 counters |
| Answer» B. thirteen mod-6 counters | |
| 161. |
Consider the following statements: Internal sorting is used if the number of items to be sorted is very large.External sorting is used if the number of items to be sorted is vary large.External sorting needs auxiliary storage.Internal sorting needs auxiliary storage. Which of the above statements are correct? |
| A. | 1 and 2 |
| B. | 2 and 3 |
| C. | 3 and 4 |
| D. | 2 and 4 |
| Answer» C. 3 and 4 | |
| 162. |
A transmission line terminates in two branches, each of length λ/4, as shown. The branches are terminated by 50Ω loads. The lines are lossless and have the characteristics impedances shown. Determine the impedance Z1 as seen by the source |
| A. | 200Ω |
| B. | 100Ω |
| C. | 50Ω |
| D. | 25Ω |
| Answer» E. | |
| 163. |
For the network shown below, if VD = 12 V and VGSQ = - 2 V value of RS will be |
| A. | 13.35 kΩ |
| B. | 3.35 kΩ |
| C. | 33.31 kΩ |
| D. | 3.95 kΩ |
| Answer» C. 33.31 kŒ© | |
| 164. |
Which junction has least junction capacitance? |
| A. | Alloy |
| B. | Grown |
| C. | Diffused |
| D. | Point contact |
| Answer» E. | |
| 165. |
5 skilled workers can build a wall in 20 days; 8 semi-skilled worker can build a wall in 25days; 10 unskilled workers can build a wall in 30 days, If a team has 2 killed, 6 semi-skilled and 5 unskilled workers, how long will it take to build the wall? |
| A. | 20 days |
| B. | 18 days |
| C. | 16 days |
| D. | 15 days |
| Answer» E. | |
| 166. |
Find Z11, |
| A. | 2 Ω |
| B. | 4 Ω |
| C. | 1 Ω |
| D. | Ω |
| Answer» D. Œ© | |
| 167. |
In a uniformly doped BJT, assume that NE, NB and NC are the emitter, base and collector dopings in atoms/cm3, respectively. If the emitter injection efficiency of the BJT is close unity, which one of the following conditions is TRUE? |
| A. | NE = NB = NC |
| B. | NE >> NB and NB > NC |
| C. | NE = NB and NB < NC |
| D. | NE < NB < NC |
| Answer» C. NE = NB and NB < NC | |
| 168. |
Two products are sold from a vending machine, which has two push buttons P1 and P2. When a button is pressed, the price of the corresponding product is displayed in a 7-segment display. If no buttons are pressed, '0' is displayed, signifying 'Rs' .0'. If only P1 is pressed, '2' is displayed, signifying 'Rs. 2'.If only P2 is pressed, '5' is displayed, signifying 'Rs. 5'.If both P1 and P2 are pressed, 'E' is displayed, signifying 'Error'. The names of the segments in the 7-segment display, and the glow of the display for '0', '2', '5' and 'E', are shown below.Consider push button pressed/not pressed is equivalent to logic 1/ 0 respectivelya segment a to g are considered as functions of P1 and P2, then which of the respectively. What are the minimum number of NOT gates and 2-input OR gates required to design the logic of the driver for this 7-segment display? |
| A. | 3 NOT and 4 OR |
| B. | 2 NOT and 4 OR |
| C. | 1 NOT and 3 OR |
| D. | 2 NOT and 3 OR |
| Answer» E. | |
| 169. |
The number of variables in a function is odd and the number of minterms with even number of 0's are same as the number of minterms with odd number at 1's, the expression formed can be represented in __________ as well as __________ form. |
| A. | Ex - OR, NOR |
| B. | Equivalence, Ex - OR |
| C. | AND, Coincidence |
| D. | OR, Ex - OR |
| Answer» C. AND, Coincidence | |
| 170. |
If a two-port network is reciprocal as well as symmetrical, which one of the following relationships is correct? |
| A. | Z12 = Z21 and Z11 = Z22 |
| B. | Y12 - Y21 and Y11 - Y22 |
| C. | AD - BC = 1 and A = D |
| D. | all of the above |
| Answer» E. | |
| 171. |
A 3 x 8 decoder with two enable inputs is to be used to address 8 blocks of memory. What will be the size of each memory block when addressed from a sixteen bit bus with two MSBs used to enable the decoder? |
| A. | 2 K |
| B. | 4 K |
| C. | 16 K |
| D. | 64 K |
| Answer» B. 4 K | |
| 172. |
A continuous time LTI system is described byAssuming zero initial conditions, the response y(t) of the above system for the input x(t) = e-2t u(t) is given by |
| A. | (et - e3t) u(t) |
| B. | (e-t - 3e-3t) u(t) |
| C. | (e-t + e-3t) u(t) |
| D. | (et + e3t) u(t) |
| Answer» C. (e-t + e-3t) u(t) | |
| 173. |
What are the ultimate purpose of minimizing logic expressions? To get small size expression.To reduce the number of variables in the given expression.To implement the function of the logic expression with least hardware.To reduce the expression for making it feasible for hardware implementation. Select the correct answer from the codes given below: |
| A. | 1 only |
| B. | 2 and 3 |
| C. | 3 only |
| D. | 3 and 4 |
| Answer» E. | |
| 174. |
The system of linear equations 4x + 2y = 1 , 2x + y = 6 has |
| A. | a unique solution |
| B. | no solution |
| C. | an infinite number of solutions |
| D. | exactly two distinct solutions |
| Answer» C. an infinite number of solutions | |
| 175. |
A linear time-invariant, causal continuous time system has a rational transfer function with simple poles at s = - 2 and s = - 4, and one simple zero at s = - 1. A unit step u(t) is applied at the input of the system. At steady state, the output has constant value of 1. The impulse response of this system is |
| A. | [exp (- 2t) + exp (-4t)] u(t) |
| B. | [-4 exp (- 2t) + 12 exp (-4t) - exp (-t)] u(t) |
| C. | [-4 exp (- 2t) + 12 exp (-4t)] u(t) |
| D. | [-0.5 exp (- 2t) + 1.5 exp (-4t)] u(t) |
| Answer» E. | |
| 176. |
A message signal given by is amplitude modulated with a carrier of frequency ωc to generate s(t) = [1 + m(t)] cos ωct |
| A. | 0.0833 |
| B. | 0.1111 |
| C. | 0.2 |
| D. | 0.25 |
| Answer» D. 0.25 | |
| 177. |
A signal with ± 10 V ranged and 1 KHz band width is being digitized using a sample and hold circuit and a 10 bit quantizer. The minimum sampling rate is : |
| A. | 62831.9 V/sec |
| B. | 125663.8 V/sec |
| C. | 31415.95 V/sec |
| D. | None |
| Answer» B. 125663.8 V/sec | |
| 178. |
The Z-transform of a particular signal is given as X(Z) = where This system after practical implementation will be |
| A. | Non Causal and Stable |
| B. | Causal and Stable |
| C. | Non Causal and Unstable |
| D. | Causal and Unstable |
| Answer» C. Non Causal and Unstable | |
| 179. |
The given characteristic polynomial s4 + s3 + 2s2 + 2s + 3 = 0 has |
| A. | zero root in RHS of s-plane |
| B. | one root in RHS of s-plane |
| C. | two roots in RHS of s-plane |
| D. | three roots in RHS of s-plane |
| Answer» D. three roots in RHS of s-plane | |
| 180. |
The Z inverse of the given Z transform is : |
| A. | unit step |
| B. | unit impulse |
| C. | unit ramp |
| D. | unit parabola |
| Answer» C. unit ramp | |
| 181. |
Given the function F(A, B, C, D) = m(0, 1, 2, 3, 4, 6, 8, 9, 10, 11, 12). The minimized form of the function can be given by : |
| A. | A + D B + C B |
| B. | (B + C)(A + B + C) |
| C. | (B + D)(A + B + C) |
| D. | C B + A D + B |
| Answer» D. C B + A D + B | |
| 182. |
A tachometer has a sensitivity of 4 V/1000 rpm. Express the gain constant of the tachometer in the units volts/(rad/sec). |
| A. | 0.0489 |
| B. | 0.0381 |
| C. | 2 |
| D. | none of these |
| Answer» C. 2 | |
| 183. |
What current does represent in pn junction diode? (where the symbols have their usual meaning) |
| A. | Forward current |
| B. | Diffusion current |
| C. | Drift current |
| D. | Reverse saturation current |
| Answer» E. | |
| 184. |
The capacitors C1, C3, C4 and C5 have a capacitance of 4 μF each and the capacitor C2 has a capacitance of 10 μF. The effective capacitance (in μF) between the points X and Y will be |
| A. | 4 μF |
| B. | 6 μF |
| C. | 3 μF |
| D. | 8 μF |
| Answer» B. 6 ŒºF | |
| 185. |
The maximum positive and negative numbers which can be represented in 2's complement form using n bits are respectively |
| A. | +(2n + 1 - 1), - (2n - 1 - 1) |
| B. | +(2n + 1 - 1), - 2n - 1 |
| C. | +2n - 1, - 2n - 1 |
| D. | +2n + 1, - (2n - 1 + 1) |
| Answer» E. | |
| 186. |
Which of the following modes can exist in a rectangular waveguide? |
| A. | TM10 |
| B. | TE10 |
| C. | TM00 |
| D. | TM01 |
| Answer» C. TM00 | |
| 187. |
Given that F(s) is the one-sided Laplace transform of f(t), the Laplace transform of f(t)dt is |
| A. | sFs - f(0) |
| B. | |
| Answer» C. | |
| 188. |
For a binary symmetric channel, the error probability Pc(0) = Pc(1) = and errors are statistically independent. The channel capacity for a signalling speed 2 bits/second. |
| A. | 2 bits/sec |
| B. | 1.69 bits/sec |
| C. | 4 bits/sec |
| D. | 1 bit/sec |
| Answer» B. 1.69 bits/sec | |
| 189. |
Assertion (A): For same drain current rating N-channel MOSFET occupies more area than p-channel MOSFET.Reason (R): Electron mobility is much higher than hole mobility. |
| 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» E. | |
| 190. |
A scheme shown below is to generate a wide band FM modulate signal. Narrow band FM has carrier frequency = 400 KHz Deviation ratio = 0.2 Wide band FM has carrier frequency = 100 MHz Deviation ratio = 6 Frequency multiplication factor is: |
| A. | 30 |
| B. | 6 |
| C. | 250 |
| D. | 12 |
| Answer» B. 6 | |
| 191. |
In a digital voltmeter the oscillator frequency is 400 kHz and the ramp voltage falls from 8 V to 0 V in 20 ms. What is the number of pulses counted by the counter? |
| A. | 800 |
| B. | 2000 |
| C. | 4000 |
| D. | 8000 |
| Answer» E. | |
| 192. |
Find RTH |
| A. | 200 Ω |
| B. | 0 Ω |
| C. | 400 Ω |
| D. | None of these |
| Answer» D. None of these | |
| 193. |
Which of the following devices is a 'hot-electron' diode? |
| A. | Thermionic tube diode |
| B. | Schottky-Barrier diode |
| C. | Thomson-Deletion diode |
| D. | Thermal electron diode |
| Answer» C. Thomson-Deletion diode | |
| 194. |
Assertion (A): There are no convergence issues with the discrete-time Fourier series in general.Reason (R): A discrete-time signal is always obtained by sampling a continuous-time signal. |
| 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» E. | |
| 195. |
If each stage has a gain of 10 dB and noise figure of 10 dB, then the overall noise figure of a two stage cascade amplifier will be |
| A. | 10 |
| B. | 1.09 |
| C. | 1 |
| D. | 10.9 |
| Answer» E. | |
| 196. |
When What is Y(j ω) ? |
| A. | |
| B. | X(j ω) H(j ω) |
| C. | X(j ω) + H(j ω) |
| Answer» C. X(j œâ) + H(j œâ) | |
| 197. |
A MOD - 2 counter, the FF has a tpd = 60 nsec. The NOR gate has a tpd of 30 nsec. The clock frequency is |
| A. | 37 MHz |
| B. | 40 MHz |
| C. | 111 MHz |
| D. | none |
| Answer» B. 40 MHz | |
| 198. |
The wavelength of a wave with propagation constant (0.1p + j0.4p)m-1 is |
| A. | 5 m |
| B. | 5p m |
| C. | |
| Answer» B. 5p m | |
| 199. |
Following figure represents |
| A. | AND |
| B. | OR |
| C. | NAND |
| D. | NOT |
| Answer» D. NOT | |
| 200. |
In the circuit, the value of the voltage source E |
| A. | -22 V |
| B. | -12 V |
| C. | +12 V |
| D. | -10 V |
| Answer» B. -12 V | |