ECE - Questions and solutions set-7
Electronics and communication Engineering Questions and solutions set-7
Question:-
Option (A)
25
Option (B)
100
Option (C)
200
Option (D)
400
Correct Option:
B
Question Solution:
F_{m} = 500 Hz, f_{s} = 1000 Hz
Frequency resolution =(f_{s}/N)
10 = (1000/N) → N = 100
Question:-
Option (A)
12.5 ohm
Option (B)
50 ohm
Option (C)
25 ohm
Option (D)
250 ohm
Correct Option:
C
Question Solution:
if Z_{L} = 0 → (K = -1)
So angle of reflection will be 180°
Now VSWR = (1+|K|)/(1-|K|) =3
|K| = (1/2) → K = ± (1/2)
but here negative sign of K is taken because position of Minima is not Changed.
So K = -(1/2) = (R_{L}-75)/(R_{L}+75)
→ R_{L} + 75 =- 2R_{L} + 2 x 75
→ 3R_{L} = 75
R_{L} = 25 ohm
Question:-
Option (A)
1
Option (B)
2
Option (C)
3
Option (D)
4
Correct Option:
B
Question Solution:
f= {(xy)'+z}'
=xy. z'
Question:-
Option (A)
5 & 5.03
Option (B)
6 & 5.83
Option (C)
5 & 6.64
Option (D)
6 & 5.32
Correct Option:
D
Question Solution:
Min^{m} bits are 2^{n} = 40 → n = 6
Entropy = log_{2} 40 = 5.32
Question:-
Option (A)
1 μF
Option (B)
10 μF
Option (C)
20 μF
Option (D)
100 μF
Correct Option:
B
Question:-
Option (A)
(t^{2}+t)
Option (B)
(2t+t)
Option (C)
2t + t^{2} + t + 1
Option (D)
Data insufficient
Correct Option:
A
Question Solution:
x(t) = t^{3} + 2t + 4t^{2}
X(S) = (6/S^{4}) + (2/S^{2}) + (4.2/S^{3}) = {(6+ 2S^{2} + 8S) / S^{3}}
Y(t) = t^{2} + t
Y(S) = (2/S^{3}) + (1/S^{2}) = {(2+S) /S^{3}}
So H(S) = (Y(S)/X(S) ) = {(S+2) / (2S^{2} + 8S +6)}
New input x(t) is x_{1}(t) = (3t^{2} + 8t + 2)
X_{1}(S) = (3.2/S^{3}) + (8/S^{2}) +(2/S) = {(6+ 8S+ 2S^{2}) / S^{3}}
New output will be
Y_{1}(S) = {(S+2) /S^{3}} = (1/S^{2}) + (2/S^{3})
Y_{1}(S) =(1/S^{2}) + (2/S^{3})
Y_{1} (t) = t+ t^{2}