MCQOPTIONS
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MCQOPTIONS
This section includes 10 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.
| 1. |
A power signal x(t) which has Power Spectral Density as a constant K, is applied to a low-pass filter-RC. Mean square value of output will be: |
| A. | 2RC/K |
| B. | K/RC |
| C. | RC/K |
| D. | K/2RC |
| Answer» E. | |
| 2. |
A digital communication system transmits a block of N bits. The probability of error in decoding a bit is α. The error event of each bit is independent of the error events of the other bits. The received block is declared erroneous if at least one of its bits is decoded wrongly. The probability that the received block is erroneous is |
| A. | N(1 - α) |
| B. | αN |
| C. | 1 - αN |
| D. | 1 – (1 - α)N |
| Answer» E. | |
| 3. |
Let X be a real-valued random variable with E[X] and E[X2] denoting the mean values of X and X2, respectively. The relation which always holds is |
| A. | (E[X])2 > E(X2) |
| B. | E(X2) ≥ (E[X])2 |
| C. | E[X2] = (E[X])2 |
| D. | E[X2] > (E[X])2 |
| Answer» C. E[X2] = (E[X])2 | |
| 4. |
In the case of a random variable dealing with non-deterministic signals |
| A. | it is a function from space of outcomes to the real/complex numbers |
| B. | it is a function with the probabilities of outcomes as random numbers |
| C. | the values assumed by signals are always deterministic |
| D. | sometimes the events associated with random variable are deterministic |
| Answer» C. the values assumed by signals are always deterministic | |
| 5. |
Match the following:A. Gaussian distribution1. Calls on a telephone channelB. Rayleigh distribution2. Random numberC. Poisson distribution3. Thermal noiseD. Uniform distribution4. Fading channel in wireless communication |
| A. | A-3, B-1, C-4, D-2 |
| B. | A-3, B-4, C-2, D-1 |
| C. | A-1, B-4, C-3, D-2 |
| D. | A-3, B-4, C-1, D-2 |
| Answer» E. | |
| 6. |
A coin is tossed 5 times. The probability of head is \(\frac{1}{2}\). The probability of exactly 2 heads is |
| A. | \(\frac{1}{16}\) |
| B. | \(\frac{3}{10}\) |
| C. | \(\frac{5}{16}\) |
| D. | \(\frac{7}{16}\) |
| Answer» D. \(\frac{7}{16}\) | |
| 7. |
A sinusoidal signal with a random phase is given by x(t) = A sin [π/2 – (2πft + θ)] with the probability density function\({P_\theta }\left( \theta \right) = \left\{ {\begin{array}{*{20}{c}} {1/2\pi ,\;\;0 \le \theta \le 2\pi }\\ {0,\;\;otherwise} \end{array}} \right.\)What is the maximum amplitude of the autocorrelation function of this signal? |
| A. | A |
| B. | A/2 |
| C. | A2 |
| D. | A2/2 |
| Answer» E. | |
| 8. |
Consider a discrete random variable assuming finitely many values. The cumulative distribution function of such a random variable is |
| A. | non-increasing function |
| B. | non-decreasing function with finitely many discontinuities and assuming values less than one |
| C. | non-decreasing function without discontinuities |
| D. | non-decreasing function assuming values larger than one |
| Answer» C. non-decreasing function without discontinuities | |
| 9. |
Let X ∈ {0,1} and Y ∈ {0,1} be two independent binary random variables. If P(X = 0) = p and P(Y = 0) = q, then P(X + Y) ≥ 1 is equal to |
| A. | pq + (1 - p)(1 - q) |
| B. | pq |
| C. | p(1 - q) |
| D. | 1 - pq |
| Answer» E. | |
| 10. |
A fair coin is tossed N times. The probability that head does not turn up in any of the tosses is |
| A. | \(\left ( \frac{1}{2} \right )^{N-1}\) |
| B. | \(1-\left ( \frac{1}{2} \right )^{N-1}\) |
| C. | \(\left ( \frac{1}{2} \right )^{N}\) |
| D. | \(1-\left ( \frac{1}{2} \right )^{N}\) |
| Answer» D. \(1-\left ( \frac{1}{2} \right )^{N}\) | |