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.
| 301. |
ROC of sequence x[n] = (3)ⁿ ∪[n] + (4)ⁿ ∪[- n - 1] |
| A. | |z| > 4 |
| B. | 3 < |z| < 4 |
| C. | |z| < 4 |
| D. | |z| > 3 |
| Answer» C. |z| < 4 | |
| 302. |
The z-transform of sequence x[n] = δ(n) is |
| A. | 1 |
| B. | ∞ |
| C. | 0 |
| D. | z |
| Answer» B. ∞ | |
| 303. |
The energy of highest value of Autocorrelation of a function 100 cos 50 πt is |
| A. | 50 |
| B. | 10 |
| C. | 200 |
| D. | zero |
| Answer» C. 200 | |
| 304. |
The Laplace transform of f(t) is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 305. |
A probability density function is given by p(x) = Ke^(-x²/2) for -∞ < x < ∞ , The value of K should be |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 306. |
The unit step response of a system is (1 - e^(at)) u(t). Then its impulse response is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 307. |
Consider these tow statements and answer follow: |
| 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 | |
| 308. |
A casual LTI system is described by the difference equation 2y[n] = αy[n - 2] - 2x[n] + βx[n -1] The system is stable only if |
| A. | |α| = 2 |β| < 2 |
| B. | |α| > 2 |β| > 2 |
| C. | |α| < 2 any value of β |
| D. | |β| < 2, any value of α |
| Answer» D. |β| < 2, any value of α | |
| 309. |
Highest value of Autocorrelation of a function 100 cos 50 πt is |
| A. | 50 |
| B. | 100 |
| C. | zero |
| D. | 100/p |
| Answer» C. zero | |
| 310. |
Which one condition is true to check the periodically for discrete time signal (where K is any integer, N is period, f₀ is frequency of signal) |
| A. | f₀ = K/N |
| B. | f₀ = K + N |
| C. | f₀ = KN |
| D. | f₀ = N/K |
| Answer» B. f₀ = K + N | |
| 311. |
Which of the following is the correct Laplace transform of the signal shown in the given figure |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 312. |
The function δ'(t - b) is a unit doublet. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 313. |
For the function f(t) = e^(-at), the Laplace transform is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 314. |
Consider the following 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» C. A is true, R is false | |
| 315. |
The two inputs to an analogue multiplier are x(t) and y(t) with fourier transforms X(f) and Y(f) respectively. The output Z(t) will have a transform Z(f) given by |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 316. |
Z transform of [(Xk±k₀)] = |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 317. |
An ac circuit has an impedance of (2 - j 9) Ω for third harmonic. The impedance for fundamental is |
| A. | 6 - j 27 Ω |
| B. | 2/3 - j 3 Ω |
| C. | 2 - j 27 Ω |
| D. | 2 - j 3 Ω |
| Answer» D. 2 - j 3 Ω | |
| 318. |
The joint probability function of two discrete random variable X and Y is given below. Variance σ² will be[Hint: σ² = E(X²) - μ² ⇒ E(X²) - (E(X))²] |
| A. | 27/6 |
| B. | 9/4 |
| C. | 40/14 |
| D. | zero |
| Answer» C. 40/14 | |
| 319. |
Fourier transform of e^(-a|t|) is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 320. |
If x^k is one sided to the right |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't Say |
| Answer» B. False | |
| 321. |
A dice is tossed. The probability that either 1 or 2 will appear is |
| A. | 1/2 |
| B. | 1/3 |
| C. | 1/6 |
| D. | 1/8 |
| Answer» D. 1/8 | |
| 322. |
A voltage V(t) is a Gaussian ergodic random process with a mean of zero and a variance of 4 volt². If it is measured by a dc meter. The reading will be |
| A. | 0 |
| B. | 4 |
| C. | 2 |
| D. | 2 |
| Answer» B. 4 | |
| 323. |
A pulse function can be represented as difference of two equal step functions. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 324. |
Assertion (A): The number ∈ such that the probability that an error is between -∈ and + ∈ is 1 is called probable error of single obserevation. Reason (R): The standard deviation is the arms value of the deviation from the arithmetic mean. |
| 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 | |
| 325. |
For the single rectangular pulse of the given figure:F(jω) = [Ad sin (ωd/2)]/(ωd/2). |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 326. |
Assertion (A): The wave shown in the given figure does not contain the dc component and even harmonics.Reason (R): If f(- t) = f(t) the wave has only cosine terms. |
| 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 | |
| 327. |
If Laplace transform of f(t) is F(s), then £[tf(t)] = |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 328. |
If n is the number of observations and r is the residue, the standard deviation σ = |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 329. |
If f(t) ↔ F(jω), f(- t) ↔ |
| A. | - F(jω) |
| B. | F(- jω) |
| C. | F(jω) |
| D. | 0.5 F(jω) |
| Answer» C. F(jω) | |
| 330. |
The units of F(jω) are volt-seconds. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 331. |
The given figure shows a square wave i(t). Then I(s) = |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 332. |
Assertion (A): The response of a network to an impluse is determined only by the parameters of the network.Reason (R): If f(t) is a unit parabolic function, its Laplace transform is 1/s³ |
| 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 | |
| 333. |
The z transform of fk = a^k is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 334. |
Choose the correct option |
| A. | var (X) = σ₂x |
| B. | σ² = E(X²) - μ² |
| C. | var (CX) = C² Var (X) |
| D. | all |
| Answer» E. | |
| 335. |
Which of the following can be impulse response of a casual system? |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 336. |
The initial value theorem is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 337. |
If ROC of x[n] is R1 then ROC of aⁿ x[n] is |
| A. | R1a |
| B. | R1/a |
| C. | a/R1 |
| D. | R1 + a |
| Answer» C. a/R1 | |
| 338. |
Consider the following as regards probability distribution function f(x). which of these are correct? |
| A. | 1 only |
| B. | 1 and 2 only |
| C. | 1, 2 and 3 |
| D. | 1 and 3 only |
| Answer» D. 1 and 3 only | |
| 339. |
A voltage V(t) which is a Gaussian ergodic random process with a mean of zero and a variance of 4 volt² is measured by a true rms meter. The reading will be |
| A. | 0 |
| B. | 4 |
| C. | 2 |
| D. | 16 |
| Answer» D. 16 | |
| 340. |
If v(t) = 0 for t < 0 and e^(-αt) for t ≥ 0 V(jω) = 1/(α + jω). |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» B. False | |
| 341. |
what will be sampling rate to aviod aliasing for the signal m(t) = 10 cos 100 πt? |
| A. | ≤ 100 n2 |
| B. | ≥ 100 n2 |
| C. | ≥1/25 sec |
| D. | ≤1/25 sec |
| Answer» E. | |
| 342. |
The Z.T. of sequence x[n] = aⁿ ∪ [n] is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 343. |
If Sn is the power associated with each frequency component and S(f) is the sum of all these powers, normalised power spectral density is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 344. |
If I(s) = 5(s+250) / s(s+100), fnal value of i(t) is |
| A. | 0 |
| B. | 2.5 |
| C. | 12.5 |
| D. | ∞ |
| Answer» D. ∞ | |
| 345. |
The signal m(t) = 10 cos 100 πt is sampled at the rate of Fs = 75 Hz, then determine signal after sampling. |
| A. | 4 cos 100 πt + 8 sin 200 πt |
| B. | 4 cos 100 πt + 8 sin 200 πt + cos 75 πt |
| C. | 4 cos 25 πt + 8 sin 50 πt + cos 75 πt |
| D. | none |
| Answer» D. none | |
| 346. |
Assertion (A): The function ke^(st) with both σ and ω positive and s > 0 depicts a sinusoid whose amplitude increases with time. Reason (R): If σ = 0, ke^(st) becomes a sinusoid. |
| 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 | |
| 347. |
If x1(t) = 2 sin πt + cos 4 πt and x2(t) = sin 5 πt + 3 sin 13 πt , then |
| A. | x1, x2 both periodic |
| B. | x1 x2 both not periodic |
| C. | x1 periodic, x2 not periodic |
| D. | x1 is not periodic ; but x2 is periodic |
| Answer» B. x1 x2 both not periodic | |
| 348. |
Transfer function of a linear system is 200 e^(-j10ω) The system is a |
| A. | distortionless Attenuator |
| B. | amplifier with Phase distortion |
| C. | distortionless Amplifier |
| D. | attenuator with Phase distortion |
| Answer» D. attenuator with Phase distortion | |
| 349. |
A function having frequency f is to be sampled. The sampling time T should be |
| A. | T = 1/2f |
| B. | T > 1/2f |
| C. | T < 1/2f |
| D. | T ≥ 1/2f |
| Answer» D. T ≥ 1/2f | |
| 350. |
For exponential function e^(-at) the Laplace transform 1/(s - a) |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | can't say |
| Answer» C. May be True or False | |