MCQOPTIONS
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MCQOPTIONS
This section includes 902 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.
| 401. |
Paley Wiener criterion for designing of filter is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 402. |
If (27s+97)/(s²+33s) is the Laplace transform of f(t) then f(0⁺) is |
| A. | 0 |
| B. | 97/3 |
| C. | 27 |
| D. | ∞ |
| Answer» D. ∞ | |
| 403. |
The unit step response of a system starting from rest is given by c(t) = 1 - e^(-2t) for t ≥ 0. The transfer function of the system is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 404. |
A box has 4 white and 3 red balls. Two balls are taken out in succession. What is the probability that both are white? |
| A. | 4/7 |
| B. | 1/2 |
| C. | 2/7 |
| D. | 1/7 |
| Answer» D. 1/7 | |
| 405. |
Consider following two statements: |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is true, R is false |
| D. | A is false, R is true |
| Answer» B. Both A and R are correct but R is not correct explanation of A | |
| 406. |
For a second order system, damping ratio ζ is such that 0 < ζ |
| A. | real but not equal |
| B. | real and equal |
| C. | complex conjugate |
| D. | imaginary |
| Answer» D. imaginary | |
| 407. |
The analog signal given below is sampled by 600 samples per second for m(t) = 3 sin 500 πt + 2 sin 700 πt, then folding frequency is |
| A. | 500 Hz |
| B. | 700 Hz |
| C. | 300 Hz |
| D. | 1400 Hz |
| Answer» D. 1400 Hz | |
| 408. |
Average power for following signal is |
| A. | 0 |
| B. | ∞ |
| C. | 1 |
| D. | 1/2 |
| Answer» E. | |
| 409. |
If f(x) = x/2 , 0 < x < 3 = 0 otherwise find E(X) |
| A. | 27/6 |
| B. | 40/14 |
| C. | 28/6 |
| D. | 0 |
| Answer» B. 40/14 | |
| 410. |
A voltage v = 100 sin ωt + 10 sin 5 ωt is applied to a pure capacitor having capacitance of 1 μF. If ω = 314 rad/sec, the current through the capacitor is |
| A. | 0.0314 cos 314 t + 0.0157 cos 1570 t |
| B. | 0.0314 sin 314 t + 0.0157 sin 1570 t |
| C. | 0.0314 cos 314 t + 0.0314 cos 1570 t |
| D. | 0.0157 cos 314 t + 0.0157 cos 1570 t |
| Answer» B. 0.0314 sin 314 t + 0.0157 sin 1570 t | |
| 411. |
The z transform of x(n) = ∪(n) |
| A. | z / (z-1) |
| B. | 1 / (z-1) |
| C. | 1 / (z+1) |
| D. | z / (z+1) |
| Answer» B. 1 / (z-1) | |
| 412. |
Fourier transform of the unit step function (i.e., u(t) = 1 for t ≥ 0 and u(t) = 0 for t < 0) is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 413. |
The final value of following is |
| A. | ∞ |
| B. | 2 |
| C. | 1 |
| D. | zero |
| Answer» D. zero | |
| 414. |
Laplace transform of e^(at) cos (at) is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 415. |
The inverse Laplace transform of 1 / (s+1)³ is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 416. |
The amplitude of the first odd harmonic of the square wave shown in the given figure is |
| A. | 4V/π |
| B. | 4V/3π |
| C. | V/π |
| D. | 0 |
| Answer» B. 4V/3π | |
| 417. |
The value of the following equation in + ve sense is |
| A. | jπ/2 |
| B. | -π/2 |
| C. | -jπ/2 |
| D. | π/2 |
| Answer» E. | |
| 418. |
A voltage wave v = 10 + 20 sin ωt + 7.5 sin 3 ω(t) is applied to a series combination of two elements. The current is i = 5 sin (ωt + 20°) + 1.5 sin (3ωt + 10°). The elements are |
| A. | R and C |
| B. | R and L |
| C. | L and C |
| D. | both inductances |
| Answer» B. R and L | |
| 419. |
The Laplace transform of sin ∝ t is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 420. |
Let x(t) ↔ X(jω) be F.T pair. The Fourier transform of the signal x(5t - 3) in terms of X(jω) is given as |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 421. |
The impulse response h[n] of a linear time invariant system is given as below. If the input to the above system is the sequence e^(jπn/4), then the output is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 422. |
The signal defined by the equations f(t) = 0 for t < 0, f(t) = E for 0 ≤ t ≤ a and f(t) = 0 for t > a is |
| A. | a step function |
| B. | a pulse function |
| C. | a shifted step function originating at t = a |
| D. | none of the above |
| Answer» C. a shifted step function originating at t = a | |
| 423. |
If X(z) = z+z¯³ / z+z¯¹, then x(n) series has |
| A. | alternates 0 |
| B. | alternate 1 |
| C. | alternate 2 |
| D. | alternate -1s |
| Answer» B. alternate 1 | |
| 424. |
Final value theroem is for sequence x[n] is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 425. |
State variables which describe a system are a unique set. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» C. May be True or False | |
| 426. |
If f1(t) |
| A. | a1F1(jω) + a2F2(jω) |
| B. | a1a2F1(jω) + F2(jω) |
| C. | a1F1(jω) - a2F2(jω) |
| D. | a1F1*(jω) + a2F2*(jω) |
| Answer» B. a1a2F1(jω) + F2(jω) | |
| 427. |
If I(s) = 5(s+250) / s(s+100) , initial value of i(t) is |
| A. | 0 |
| B. | 5 A |
| C. | 10 A |
| D. | - 5A |
| Answer» C. 10 A | |
| 428. |
The Laplace transform of cos ωt is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 429. |
Assertion (A): The Fourier series of the wave shown in the figure does not contain even harmaonics.Reason (R): If f(t) = - f(t ± T/2) the function is said to have half wave symmetry. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is true, R is false |
| D. | A is false, R is true |
| Answer» C. A is true, R is false | |
| 430. |
A voltage v(t) which is a gaussian ergodic random process witha mean of zero and a varance of 4 volt² is measured by a meter which first square and then reads its dc component. The reading will be |
| A. | 0 |
| B. | 4 |
| C. | 16 |
| D. | 2 |
| Answer» C. 16 | |
| 431. |
Half wave sysmmetry means f(t) = - f(t ± T/2). |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 432. |
If X(z) = (1 - αz¯¹)¯¹ and |a| < |z|, the initial value x₀ = 0 |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» C. May be True or False | |
| 433. |
The following signal is |
| A. | periodic for t > 0 |
| B. | non-periodic |
| C. | periodic for t < 0 |
| D. | depends on t |
| Answer» C. periodic for t < 0 | |
| 434. |
For the discrete time system of the given figure |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 435. |
If i(t) is a time varying current, then following is |
| A. | initial current |
| B. | initial charge |
| C. | initial flux leakages |
| D. | initial voltage |
| Answer» C. initial flux leakages | |
| 436. |
The function x(t) is shown in the given figure. Even and odd parts of a unit step function ∪ (t) are respectively, |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 437. |
The Laplace transform of the waveform shown in the below figure is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 438. |
Energy density spectrum of a gate GT(t) function is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 439. |
Energy density spectrum of x[n] = aⁿ∪[n] for -1 < a < + 1 is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 440. |
Fourier transform of the function f(t) = 1 is |
| A. | 2π δ (ω) |
| B. | π δ (ω) |
| C. | δ(ω)/2π |
| D. | δ(ω)/π |
| Answer» B. π δ (ω) | |
| 441. |
If f(t) and F(jω) form a transform pair, then as per symmetry in Fourier transforms |
| A. | F(jt) ↔ 2pf (- ω) |
| B. | F(jt) ↔ πf (ω) |
| C. | F(jt) ↔ πf (ω)/2 |
| D. | F(jt) ↔ πf (-ω)/2 |
| Answer» B. F(jt) ↔ πf (ω) | |
| 442. |
The exponential form of Fourier series is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 443. |
(SI - A)¯¹ = adj(sI - A)/det (sI - A) |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 444. |
δ(t) is a |
| A. | energy signal |
| B. | power signal |
| C. | neither energy nor power |
| D. | none |
| Answer» C. neither energy nor power | |
| 445. |
If F(s) = 10 / s²+4s+4, f(t) = |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 446. |
Assertion (A): A half cycle of sine wave can be expressed as sum of sine wave and another sine wave shifted by T/2 where T is the time period.Reason (R): The function u(t - t₀) - u(t - t₀ - T) is a gate function occuring at t = t₀ and of duration T. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is true, R is false |
| D. | A is false, R is true |
| Answer» C. A is true, R is false | |
| 447. |
The function A e^(st) where s = s + jω represents |
| A. | A phasor whose magnitude changes with time |
| B. | A phasor whose frequency is ω |
| C. | A phasor rotating in counterclockwise direction at angular frequency ω and whose magnitude increases with t |
| D. | A phasor rotating in clockwise direction at angular frequency ω and whose magnitude increases with t |
| Answer» D. A phasor rotating in clockwise direction at angular frequency ω and whose magnitude increases with t | |
| 448. |
The Laplace transform of (tⁿ-1) where n is integer is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 449. |
In an ac circuit the fundamental component of current wave lags the corresponding voltage wave by 20°. The third harmonic component of current wave lags the corresponding voltage by an angle. |
| A. | less than 20° |
| B. | more than 20° |
| C. | equal to 20° |
| D. | equal to or more than 20° |
| Answer» C. equal to 20° | |
| 450. |
The distance of a synchronous satellite from Earth's surface is __________ km. |
| A. | 300 |
| B. | 10000 |
| C. | 35900 |
| D. | 5 |
| Answer» D. 5 | |