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Electronics and Communication Engineering - Signals and Systems

Exercise : Signals and Systems - Section 3
41.
A voltage v = 5 + 50 sin ωt/ + 5 sin 5 &omegat is applied to a pure capacitor of capacitance 1 ωF. If f/= 314 rad/sec, current is
1 + 0.0157 cos 314 t + 0.00785 cos 1570 t
0.0157 cos 314 t + 0.00785 cos 1570 t
0.0157 sin 314 t + 0.00785 sin 1570 t
0.0157 sin (314 t / + 45°) + 0.00785 sin (1570 t + 45°)
Answer: Option
Explanation:

.

42.
The stationary process has
all the statistical Properties dependent on time.
all the statistical Properties independent of time.
aime average is equal to ensemble average.
zero variance.
Answer: Option
Explanation:

where f(x) is probability density function.

43.
If x1(t) = 2 sin pt + cos 4 pt and x2(t) = sin 5 pt + 3 sin 13 pt then
x1, x2 both periodic
x1 x2 both not periodic
x1 periodic, x2 not periodic
x1 is not periodic ; but x2 is periodic
Answer: Option
Explanation:

.

44.
An ac network has a power factor of 0.8 leading if the applied wave is of fundamental frequency. If the applied wave contains third and fifth harmonics, the overall power factor will be
0.8 leading
less than 0.8 leading
more than 0.8 leading
0.8 leading or more
Answer: Option
Explanation:

As frequency increases, XC decreases and power factor improves.

45.

Assertion (A): A sweep circuit operates by virtue of recurring transient phenomenon.

Reason (R): Transients are always undesirable.

Both A and R are correct and R is correct explanation of A
Both A and R are correct but R is not correct explanation of A
A is true, R is false
A is false, R is true
Answer: Option
Explanation:

Many circuits operate due to transient phenomena. Hence R is wrong.

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