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.
| 501. |
Consider the circuit shown below of 2 : 1 MUX is given by the function g = ac + bcThen f is : |
| A. | X ‚äï Y |
| B. | XY + EXY |
| C. | XE + XY |
| D. | none of these |
| Answer» C. XE + XY | |
| 502. |
Four messages band limited to W, W, 2W and 3W respectively are to be multiplex using Time Division Multiplexing (TDM). The minimum bandwidth required for transmission of this TDM signal is |
| A. | W |
| B. | 3W |
| C. | 6W |
| D. | 7W |
| Answer» D. 7W | |
| 503. |
Find equivalent resistance. Each resistance is l Ω |
| A. | 5/12 Ω |
| B. | 5/6 Ω |
| C. | 6/5 Ω |
| D. | 6/10 Ω |
| Answer» C. 6/5 Œ© | |
| 504. |
The surface charge density on a conductor is 1.55 x 10-9C/m2. The conductor is immersed in water with ε = 78ε0.The electric field will be __________ . |
| A. | 3 V/m |
| B. | 1.55 V/m |
| C. | 2 V/m |
| D. | 2.25 V/m |
| Answer» E. | |
| 505. |
Consider a baseband binary PAM receiver shown below. The additive channel noise n(t) is whit with power spectral density SN(f) = N0/2 = 10-20 W/Hz. The low-pass filter is ideal with unity gain and cutoff frequency 1 MHz. Let Yk represent the random variable y(tk).Yk = nNk if transmitted bit bk = 0Yk = a + Nk if transmitted bit bk = 1Where Nk represents the noise sample value. The noise sample has a probability density function, PNk(n) = 0.5ae-a|n| (This has mean zero and variance 2/a2). Assume transmitted bits to be equiprobable and threshold z is set to a/2 = 10-6 V.The value of the parameter a (in V-1) is |
| A. | 1010 |
| B. | 107 |
| C. | 1.414 x 10-10 |
| D. | 2 x 10-20 |
| Answer» C. 1.414 x 10-10 | |
| 506. |
Which of the following Boolean Expression correctly represents the relation between P, Q, R and M1? |
| A. | M1 = (P OR Q) XOR R |
| B. | M1 = (P AND Q) XOR R |
| C. | M1 = (P NOR Q) XOR R |
| D. | M1 = (P XOR Q) XOR R |
| Answer» E. | |
| 507. |
In the given figure.The damping coefficient for the given circuit is __________ . |
| A. | 43497 |
| B. | 43556 |
| C. | 2 |
| D. | 1 |
| Answer» B. 43556 | |
| 508. |
In TV transmission the modulation schemes for video and audio are respectively |
| A. | FM and AM |
| B. | FM and FM |
| C. | AM and FM |
| D. | AM and AM |
| Answer» D. AM and AM | |
| 509. |
The Causal system given below is __________ H(z) = 6 + z-1 - z-2 |
| A. | maximum phase |
| B. | minimum phase |
| C. | mixed phase |
| D. | none of these |
| Answer» C. mixed phase | |
| 510. |
For a Hertz dipole antenna, the Half Power Beam Width (HPBW) in the E-plane is |
| A. | 360° |
| B. | 180° |
| C. | 90° |
| D. | 45° |
| Answer» C. 90¬∞ | |
| 511. |
The Nyquist sampling rate for the signal s(t) = is given by |
| A. | 400 Hz |
| B. | 600 Hz |
| C. | 1200 Hz |
| D. | 1400 Hz |
| Answer» D. 1400 Hz | |
| 512. |
Consider a multiplexer with X and Y as data inputs and Z as control input. Z = 0 selects input X and Z = 1 selects input Y. What are the connections required to realize the 2-variable Boolean function f = T + R, without using any additional hardware? |
| A. | R to X, 1 to Y, T to Z |
| B. | T to X, R to Y, T to Z |
| C. | T to X, R to Y, 0 to Z |
| D. | R to X, 0 to Y, T to Z |
| Answer» B. T to X, R to Y, T to Z | |
| 513. |
Period of the signal is: |
| A. | 8 |
| B. | 1 |
| C. | 24 |
| D. | 16 |
| Answer» D. 16 | |
| 514. |
Consider the following circuit using an ideal OP-AMP. The I-V characteristics of the diode is described by the relation where VT = 25mV, I0 = 1mA and V is the voltage across the diode (taken as positive for forward bias). For an input voltage V1 = - 1 V, the output voltage V0 is |
| A. | 0 V |
| B. | 0.1 V |
| C. | 0.7 V |
| D. | 1.1 V |
| Answer» C. 0.7 V | |
| 515. |
A uniform plane wave is described by the equation H = A/m. If the velocity of the wave is 2 x 108 m/s and εr = 1.8, then. The frequency of the wave is |
| A. | 1.5 x 106 Hz |
| B. | 1.5 x 108 Hz |
| C. | 106 Hz |
| D. | 107 Hz |
| Answer» E. | |
| 516. |
Assertion (A): Cut-in voltage for Germanium diode is greater than that for silicon diode.Reason (R): Germanium diode has a higher reverse saturation current than silicon diode. |
| 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. | |
| 517. |
The Table given below is the mark obtained by 2 students in 8 different subjects. The coefficient of correlation is: |
| A. | -0.4748 |
| B. | 0.4748 |
| C. | -0.0338 |
| D. | 0.0338 |
| Answer» B. 0.4748 | |
| 518. |
For real values of x, the minimum value of the function f(x) exp (x) + exp (- x) is |
| A. | 2 |
| B. | 1 |
| C. | 0.5 |
| D. | 0 |
| Answer» B. 1 | |
| 519. |
Consider the following BJT circuit:hie = 2 k ohmhfe = 100hre = 2.5 x 10-4The value of Ri is : |
| A. | 2.46 kΩ |
| B. | 2.88 kΩ |
| C. | 200 Ω |
| D. | 18.48 Ω |
| Answer» B. 2.88 kŒ© | |
| 520. |
Which of the following does not show non-linear V-I characteristics? |
| A. | Schottky diode |
| B. | Tunnel diode |
| C. | Thermister, at a fixed temperature |
| D. | p-n junction diode |
| Answer» D. p-n junction diode | |
| 521. |
The point P in the following figure is stock at 1. The output f will be |
| A. | ABC |
| B. | A |
| C. | AB C |
| D. | A |
| Answer» E. | |
| 522. |
The signal x(t) is described by Two of the angular frequencies at which its fourier transform becomes zero are |
| A. | p, 2p |
| B. | 0.5p, 1.5p |
| C. | 0, p |
| D. | 2p, 2.5p |
| Answer» B. 0.5p, 1.5p | |
| 523. |
A transmitter radiates a power 20 KW and its base current is 18A. The radiation resistance of the antenna is |
| A. | 1111 Ω |
| B. | 900 Ω |
| C. | 75 Ω |
| D. | 62 Ω |
| Answer» E. | |
| 524. |
Which of the following devices is used at the first stage of an electronic voltmeter? |
| A. | BJT |
| B. | SCR |
| C. | MOSFET |
| D. | UJT |
| Answer» D. UJT | |
| 525. |
The equivalent T circuit of this coupled network is shown in figure. Find the values of ZA, ZB and ZC. |
| A. | -j, 6j, 2j |
| B. | -j, 2j, 6j |
| C. | j, 2j, - 6j |
| D. | j, 2j, 6j |
| Answer» C. j, 2j, - 6j | |
| 526. |
Consider an angle modulated signalx(t) = 6cos[2p x 106t + 2sin(8000pt) + 4cos(8000pt)] VThe average power of x(t) is |
| A. | 10W |
| B. | 18W |
| C. | 20W |
| D. | 28W |
| Answer» C. 20W | |
| 527. |
Consider the following statements, regarding an OP AMP: All types of negative feedback reduce non-linear distortion.All types of negative feedback reduce the output offset voltage.Non-inverting (current and voltage) feedback increases the input impedance.Inverting (current and voltage) feedback decreases input impedance. Which of the above statements is/are correct? |
| A. | 1 only |
| B. | 2 and 3 only |
| C. | 2 and 4 only |
| D. | 1, 2, 3 and 4 |
| Answer» E. | |
| 528. |
For a medium σ = 2.1 x 10-4 mho/m and ε = 80 e0 at a frequency of 5 GHz its loss tangent is |
| A. | 1 x 10-5 |
| B. | 9.45 x 10-6 |
| C. | 1.31 x 10-4 |
| Answer» C. 1.31 x 10-4 | |
| 529. |
The number of roots of s3 + 2s2 + 7s + 3 = 0 in the left half of the s-plane is : |
| A. | zero |
| B. | one |
| C. | two |
| D. | three |
| Answer» E. | |
| 530. |
Consider a system whose input x and output y are related by the equationy(t) = x(t - t)h(2t)dtwhere h(t) is shown in the graphwhich of the following four properties are possessed by the system?BIBO: Bounded input gives a bounded outputCausal: The system is causalLP: The system is low passLTI: The system is linear and time invariant |
| A. | Causal, LP |
| B. | BIBO, LTI |
| C. | BIBO, Causal, LTI |
| D. | LP, LTI |
| Answer» C. BIBO, Causal, LTI | |
| 531. |
Multiple member of antennas are arranged in arrays in order to enhance what property? |
| A. | Both directivity and bandwidth |
| B. | Only directivity |
| C. | Only bandwidth |
| D. | Neither directivity nor bandwidth |
| Answer» C. Only bandwidth | |
| 532. |
Find I for circuit shown below |
| A. | 0.125 |
| B. | 0.041666666666667 |
| C. | 0.083333333333333 |
| D. | 0 |
| Answer» D. 0 | |
| 533. |
The process of extension of a single-crystal surface by growing a film in such a way that the added atoms form a continuation of the single-crystal structure is called |
| A. | Ion implantation |
| B. | Chemical vapour deposition |
| C. | Electroplating |
| D. | Epitaxy |
| Answer» E. | |
| 534. |
In 8085 microprocessor system, can an input and output port have same port address? |
| A. | Yes |
| B. | No |
| C. | Insufficient data |
| D. | None of these |
| Answer» B. No | |
| 535. |
Which of the following is equivalent to x? |
| A. | x EX-OR 0 |
| B. | x EX-NOR 0 |
| C. | 1 NOR x |
| D. | x AND x |
| Answer» C. 1 NOR x | |
| 536. |
Which of the following may result in instability problem? |
| A. | Large error |
| B. | High selectivity |
| C. | High gain |
| D. | Noise |
| Answer» D. Noise | |
| 537. |
The reflection coefficient on a 500 m long transmission line has a phase angle of - 150°. If the operating wavelength is 150 m, what will be the number of voltage maxima on the line? |
| A. | 0 |
| B. | 3 |
| C. | 6 |
| D. | 7 |
| Answer» D. 7 | |
| 538. |
A rectangular waveguide of internal dimensions (a = 4 cm and b = 3) is to be operated in TE11 mode. The minimum operating frequency is |
| A. | 6.25 GHz |
| B. | 6.0 GHz |
| C. | 5.0 GHz |
| D. | 3.75 GHz |
| Answer» B. 6.0 GHz | |
| 539. |
At t = ‚àû; VR2 and VC will be |
| A. | 4, 4 |
| B. | 2, 4 |
| C. | 0, 2 |
| D. | 2, 0 |
| Answer» C. 0, 2 | |
| 540. |
The JFET in the circuit shown in figure has an IDSS = 10 mA and Vp = -5 V. The value of the resistance Rs for a drain current IDS = 6.4 mA is (select the nearest value) |
| A. | 150 Ω |
| B. | 150 Ω |
| C. | 560 Ω |
| D. | 1 kΩ |
| Answer» B. 150 Œ© | |
| 541. |
Consider the following: Coupling capacitorEmitter by-pass capacitorEmitter to base diffusion capacitance of the BJTStray capacitance of the circuit. Which of these components in a R-C coupled amplifier control the lower cut-off frequency of the amplifier? |
| A. | 1 and 2 |
| B. | 2 and 3 |
| C. | 3 and 4 |
| D. | l and 4 |
| Answer» B. 2 and 3 | |
| 542. |
In the circuit shown, all the transmission line sections are lossless. The Voltage Standing Wave Ration (VSWR) on the 60W line is |
| A. | 1 |
| B. | 1.64 |
| C. | 2.5 |
| D. | 3 |
| Answer» C. 2.5 | |
| 543. |
An astable multivibrator circuit using IC 555 timer is shown below. Assume that the circuit is oscillating steadilyThe voltage Vc across capacitor varies between |
| A. | 3 V to 5 V |
| B. | 3 V to 6 V |
| C. | 3.6 V to 6 V |
| D. | 3.6 V to 5 V |
| Answer» C. 3.6 V to 6 V | |
| 544. |
With respect to the following 555 timer circuit what will be the value of RA and R such that the LED turns on for a duration of 10 ms every time it receives negative trigger pulse. LED operating current = 20 mA, Vf = 1.4 V, Vo on = 13.4 V and C = 0.22 nf |
| A. | 41.4 KΩ, 600 Ω |
| B. | 45 KΩ, 630 Ω |
| C. | 43.5 KΩ, 580 Ω |
| D. | 44.9 KΩ, 600 Ω |
| Answer» B. 45 KŒ©, 630 Œ© | |
| 545. |
Assertion (A): Ideal current sources and ideal voltage sources do not exist in reality.Reason (R): All sources have finite internal impedances. |
| 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 | |
| 546. |
The equivalent of the block diagram in figure is given in |
| A. | Figure (a) |
| B. | Figure (b) |
| C. | Figure (c) |
| D. | Figure (d) |
| Answer» E. | |
| 547. |
Which of the following factors are responsible to design IC logic gates to operated at a fixed supply voltage of 5 volts? Low heating of IC logic gatesCompatibility with other logic gatesSatisfactory and safe operationStandardization from IC manufacturing point of view. Select the correct answer from the codes given below: |
| A. | 1 only |
| B. | 2 only |
| C. | 2 and 3 |
| D. | 3 and 4 |
| Answer» D. 3 and 4 | |
| 548. |
Poynting vector is associated with |
| A. | flux in magnetic field |
| B. | power flow in electrostatic field |
| C. | current in electrostatic field |
| D. | charge in electrostatic field |
| Answer» C. current in electrostatic field | |
| 549. |
(9)11 x (9)13 x(9)15 = (?)16 |
| A. | 933 |
| B. | 2D9 |
| C. | 339 |
| D. | 9AB |
| Answer» C. 339 | |
| 550. |
The equivalent form of the logical expression (ABC + ABC + ABC + ABC + ABC) is: |
| A. | C + (A ‚äï B) |
| B. | (A + B + C)(A + B + C) |
| C. | (A + B + C)(A + B + C)(A + B + C) |
| D. | (A + B + C)(A + B + C)(A + B + C) |
| Answer» E. | |