Electronics and Communication Engineering - Signals and Systems

6.
In terms of signum function sgn(t), unit step function u(t) =
1 + sgn(t)
1 - sgn(t)
0.5 + 0.5 sgn(t)
0.5 - 0.5 sgn(t)
Answer: Option
Explanation:
No answer description is available. Let's discuss.

7.
Choose correct option
var (X + Y) = Var (X) + Var (Y)
var (X - Y) = Var (X) + Var (Y)
var (X + Y) = Var (X) x Var (Y)
Both (a) and (b)
Answer: Option
Explanation:

These are standard property.


8.
If I(s) = , fnal value of i(t) is
0
2.5
12.5
Answer: Option
Explanation:

.


9.
If sequence y(n) = x(-n) then it is
Causal
Non-Causal
Depends on x(-n)
None
Answer: Option
Explanation:

If n is +ve then causal, and if n is -ve then non-causal.


10.
In the given figure 15.6 shows a series, R - C circuit fed by a current source i(t). There is an initial voltage v0. across the capacitor. The system
is linear
is non linear
may be linear or non linear
is linear only if v0 is zero
Answer: Option
Explanation:

Due to presence of v0 the response will not proportional to cause. Hence v0 must be zero if it is a linear system.