Electronics and Communication Engineering - Signals and Systems

Exercise :: Signals and Systems - Section 1

26.

A function having frequency f is to be sampled. The sampling time T should be

A.
B.
C.
D.

Answer: Option C

Explanation:

Sampling frequency must be more than 2f. Therefore .

27.

The final value theorem is

A.
B.
C.
D.

Answer: Option A

Explanation:

£f(t) =

£^-1F(s) = f(t)

£[a f₁(t) + bf₂(t)] = aF₁(s) + bF₂(s)

where

£[f(t - T)] = e^-sT F(s)

£[e^-at f(t)] = F(s + a)

Initial value theorem

Final value theroem

Convolution Integral

where t is dummy variable for t.

28.

If

A.	- 12
B.	12
C.	20
D.	- 20

Answer: Option A

Explanation:

det.|A| = 3(8 - 12) = - 12.

29.

Inverse Fourier transform of sgn (ω) is

A.
B.	1
C.	U(t)
D.

Answer: Option A

Explanation:

By duality Property.

30.

If I (s) , the final value of i(t) is

A.	5A
B.	12.5 A
C.	0.05 A
D.	1250 A

Answer: Option B

Explanation:

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