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.
| 701. |
If f1(t) ↔ F1 (jω) and f2(t) ↔ F2(jω), then f1(t)↔ f2(t) |
| A. | F1(jω) F2(jω) |
| B. | F1(jω)*F2(jω) |
| C. | |
| Answer» D. | |
| 702. |
Final value theorem is used to find |
| A. | steady state value of system output |
| B. | initial value of output |
| C. | transient beaviour of output |
| D. | none of these |
| Answer» B. initial value of output | |
| 703. |
In what range should Re(s) remains so that Laplace transform of the function e(a + 2)t + 5 exists? |
| A. | Re(s) > a + 2 |
| B. | Re(s) > a + 7 |
| C. | Re(s) < a |
| D. | Re(s) > a + 5 |
| Answer» B. Re(s) > a + 7 | |
| 704. |
The auto correlation of a sampling function is a |
| A. | triangular function |
| B. | gate function |
| C. | signum function |
| D. | none of the above |
| Answer» C. signum function | |
| 705. |
If , then x(n) series has |
| A. | alternates 0 |
| B. | alternate 1 |
| C. | alternate 2 |
| D. | alternate -1s |
| Answer» B. alternate 1 | |
| 706. |
For Binomial Distribution |
| A. | mean = np, Variance = npq |
| B. | mean = npq, Variance = np |
| Answer» B. mean = npq, Variance = np | |
| 707. |
Auto correlation function |
| A. | is an even function of t |
| B. | is an odd function of t |
| C. | may be an even or odd function of t |
| D. | is both an odd and even function of t |
| Answer» B. is an odd function of t | |
| 708. |
A linear discrete time system has the char. equation z3 - 0.81z = 0, the system is |
| A. | stable |
| B. | marginally stable |
| C. | unstable |
| D. | stability cannot be assessed from the given information |
| Answer» B. marginally stable | |
| 709. |
If then, f(0+) and f(‚àû) are given by |
| A. | 0 and 2 |
| B. | 2, 0 |
| C. | 0, 1 |
| D. | , 0 |
| Answer» C. 0, 1 | |
| 710. |
If the number of ways an event may result ins analysed into m successes and n failures, each equally likely to occur, the probability of success in a single trial is m( m + n) |
| A. | 1 |
| B. | |
| Answer» B. | |
| 711. |
The inverse Laplace transform of is |
| A. | t2 e-t |
| B. | |
| Answer» C. | |
| 712. |
x = AX + Bu is a state equation. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 713. |
If v(t) = 0 for t < 0 and e-at for t ≥ 0 V(jω) = 1/(a + jω). |
| A. | 1 |
| B. | |
| Answer» B. | |
| 714. |
If function f(t) has an initial value f(0-) at t = 0-, the Laplace transform of is |
| A. | sF(s) - f(0-) |
| B. | sF(s) + f(0-) |
| C. | s2F(s) - f(0-) |
| D. | s2F(s) + f(0-) |
| Answer» B. sF(s) + f(0-) | |
| 715. |
For exponential function e-at the Laplace transform 1/(s - a) |
| A. | 1 |
| B. | |
| Answer» C. | |
| 716. |
If I(s) = , fnal value of i(t) is |
| A. | 0 |
| B. | 2.5 |
| C. | 12.5 |
| D. | ‚àû |
| Answer» D. ‚àû | |
| 717. |
If a sequence is causal then ROC is (where a is any number) |
| A. | |z| > a |
| B. | |z| < a |
| C. | |z| = a |
| D. | Entire Plane |
| Answer» B. |z| < a | |
| 718. |
In the periodic train of rectangular pulses F0 = (V0/T)d |
| A. | 1 |
| B. | |
| Answer» B. | |
| 719. |
For matrix A, A-1 A = 1 |
| A. | 1 |
| B. | |
| Answer» B. | |
| 720. |
Assertion (A): If a wave v = A1 + A2 sin ωt is applied to a pure capacitor the current wave isi = A3 sin(ωt + 90°) Reason (R): A capacitor presents infinite impedance to dc. |
| 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 | |
| 721. |
Given, Lf(t) = F(s) ‚áí which of the following expression are correct? L[f(t - a) ‚à™ (t - a)] = F(s)e-saL(t - a)f(t) = as F(s) Select the correct answer using the codes given below |
| A. | 1, 2, 3 |
| B. | 1, 2, 4 |
| C. | 2, 3, 4 |
| D. | 1, 3, 4 |
| Answer» C. 2, 3, 4 | |
| 722. |
The data about p the pull required to lift a weight wby a pulley block isThe linear law p = a + bw is |
| A. | 3.2 + 0.171 w |
| B. | 2.28 + 0.1879 w |
| C. | 1.2 + 0.25 w |
| D. | 0.6 + 0.3 w |
| Answer» C. 1.2 + 0.25 w | |
| 723. |
Assertion (A): δ(t - b) is an impulse occuring at t = bReason (R): Intergal of unit impulse gives unit step function. |
| 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 | |
| 724. |
The function (sin x)/x |
| A. | has a period 2p, decays with increasing x and has zeros at np, n = ± 1, ± 2 |
| B. | has a period p |
| C. | has a period p/2 |
| D. | has a period 2p, decays with increasing x, is an even function and has zeros at np, n = ± 1, ± 2 |
| Answer» E. | |
| 725. |
The eign values of n x n matrix A are the root of the characteristic equation 1λI - AI = 0 |
| A. | 1 |
| B. | |
| Answer» B. | |
| 726. |
The energy of constant amplitude complex valued exponential sequence is ... |
| A. | A2 |
| B. | ‚àû |
| C. | 1 |
| D. | 0 |
| Answer» C. 1 | |
| 727. |
The energy of highest value of Autocorrelation of a function 100 cos 50 pt is |
| A. | 50 |
| B. | 10 |
| C. | 200 |
| D. | zero |
| Answer» C. 200 | |
| 728. |
Out of the three transforms viz. Z-transform, Laplace transform and Fourier transform |
| A. | all three are used in continuous time domain |
| B. | all three are used in both continuous time domain and discrete time domain |
| C. | Z transform is used in continuous time domain while Laplace and Fourier transforms are used in discrete time domain |
| D. | Z transform is used is discrete time domain while Laplace and Fourier transforms are used in continuous time domain |
| Answer» E. | |
| 729. |
The function δ'(t - b) is a unit doublet. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 730. |
The units of F(jω) are volt-seconds. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 731. |
If a function has only cosine terms, it must satisfy the equation |
| A. | f(t) = -f(t) |
| B. | f(-t) = f(t) |
| C. | f(-t) = -f(t) |
| D. | none of the above |
| Answer» C. f(-t) = -f(t) | |
| 732. |
unit step is a |
| A. | energy signal |
| B. | power signal |
| C. | neither energy nor power signal |
| D. | none |
| Answer» C. neither energy nor power signal | |
| 733. |
If , f(t) = |
| A. | 10 te-2t |
| B. | 10 t2e-2t |
| C. | 10 e-2t |
| D. | 5 t2e-2t |
| Answer» B. 10 t2e-2t | |
| 734. |
The integral of k u(t) is |
| A. | a ramp of slope k |
| B. | a ramp of slope 1/k |
| C. | k δ(t) |
| Answer» B. a ramp of slope 1/k | |
| 735. |
Assertion (A): The conditions under which it is possible to write Fourier series of a periodic function are called Drichlet conditions. Reason (R): If f(t) = - f(- t), it is refereed to as odd 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 | |
| 736. |
For a signal x(t) the F.T. is X(f). Then inverse F.T of X(3f + 2) is given by |
| A. | |
| B. | |
| Answer» C. | |
| 737. |
ROC of sequence x[n] = δ[n] is |
| A. | Not exist |
| B. | z = 0 |
| C. | Entire Plane |
| D. | Entire Plane expect z = 0, z = ‚àû |
| Answer» D. Entire Plane expect z = 0, z = ‚àû | |
| 738. |
An ac network has a power factor of 0.8 lagging for fundamental frequency. If the applied voltage contains thrid and fifth harmonics, the overall power factor will be |
| A. | more than 0.8 lagging |
| B. | 0.8 lagging |
| C. | less than 0.8 lagging |
| D. | 0.8 lagging or less |
| Answer» D. 0.8 lagging or less | |
| 739. |
Assertion (A): When a function f(t) is represented as exponential Fourier series, the set of complex coefficients Fn is called frequency spectrum of f(t)Reason (R): Frequency spectrum is also called line spectrum. |
| 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 | |
| 740. |
Fourier transform F(jω) of an arbitrary signal has the property |
| A. | F(jω) = F(- jω) |
| B. | F(jω) = - F(- jω) |
| C. | F(jω) = F*(- jω) |
| D. | F(jω) = - F*(jω) |
| Answer» C. F(jœâ) = F*(- jœâ) | |
| 741. |
The solution of state equations using Laplace transform is |
| A. | x(t) = φ(t) x(0) + L-1 [φ(s) Bu(s)] |
| B. | x(t) = φ(s) x(0) + L-1 [φ(s) Bu(s)] |
| C. | x(t) = eAt X(0) + eA(t-t) Bu(t)dt |
| D. | Both (a) and (b) |
| Answer» E. | |
| 742. |
Assertion (A): Transient periods are of short duration but can result in dangerously high voltages and currents.Reason (R): Circuit equations in transient analysis are integral differential equations. |
| 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 | |
| 743. |
Assertion (A): If , the final value of i(t) is 2AReason (R): As per final value theroem |
| 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» E. | |
| 744. |
Z transformer of |
| A. | aX(z) - bY(z) |
| B. | aX(z) + bY(z) |
| C. | aX(z) + bY(z) + a/b |
| D. | aX(z) + bY(z) + bY(z) - a/b |
| Answer» C. aX(z) + bY(z) + a/b | |
| 745. |
Fourier transform of f(t) = |
| A. | jω F(f) |
| B. | 2pf F(f) |
| C. | F'(f) |
| D. | None |
| Answer» B. 2pf F(f) | |
| 746. |
cos(nω1t) = |
| A. | 0.5 (ejnω1t + e-jnω1t) |
| B. | 0.05 |
| C. | (ejnω1t + e-jnω1t) |
| D. | (ejnω1t - e-jnω1t) |
| Answer» B. 0.05 | |
| 747. |
A signum function is |
| A. | zero for t greater than zero |
| B. | zero for t less than zero |
| C. | unity for t greater than zero |
| D. | 2‚à™(t) - 1 |
| Answer» E. | |
| 748. |
If f (t) is an even function, then in th form |
| A. | 1 |
| B. | |
| Answer» B. | |
| 749. |
The value of Integral (t2 + 2) δ(t - 3)dt is equal to |
| A. | 11 |
| B. | 3 |
| C. | 9 |
| D. | 0 |
| Answer» E. | |
| 750. |
If x1(t) = 2 sin pt + cos 4 pt and x2(t) = sin 5 pt + 3 sin 13 pt 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 | |