Electronics and Communication Engineering - Exam Questions Papers

1.
If we manage to __________ our natural resources, we would leave a better planet for our children.
uphold
restrain
Cherish
conserve
Explanation:

The clue in this sentence is 'If we manage to __________ our natural resources' and 'better planet'.

This implies that the blank should be filled by a word which means 'preserve' or 'keep for long time'.

Therefore the word 'conserve' is the right answer.

2.
(2)3 + (3)4 = (?)5
4
11
none of these
not possible
Explanation:

(2)3 + (3)4 = 2 + 3 = 5 and (10)5 = 51 + 0 = 5

(2)3 + (3)4 = (10)5 .

3.
If g(t) = e- p t2 then G(0) is __________ (where g(t)⇔ G(f)
unity
impulse at f = 0
Explanation:

The signal g(t) given above is a Gaussian pulse, and it satisfies the relation.

Therefore, its fourier transform is same as the signal itself in frequency domain.

i.e. G(f) = e-pf2

Hence G(f)|f = 0 = e-p(0) = 1.

4.
The open loop transfer function of a unity feedback system is: The range of K for which the system is stable is
13 > K > 0
-6 < K < ∞
Explanation:

Apply R-H.

5.
A discrete time linear shift-invariant system has an impulse response h[n] with h[0] = 1, h[1] = - 1, h[2] - 2, and zero otherwise. The system is given an input sequence x[n] with x[0] - x[2] - 1, and zero otherwise. The number of nonzero samples in the output sequence y[n], and the value of y[2] are, respectively
5, 2
6, 2
6, 1
5, 3