Communication Engineering - Online Test
Q1. 
In the following network, the switch is closed at t = 0- and the sampling starts from t = 0. The sampling frequency is 10 Hz.
The samples x(n), n = (0, 1, 2, ...) are given by
Answer : Option B
Explaination / Solution:
No Explaination.
Q2. Let the signal 
be passed through an LTI system with frequency
response H(𝜔), as given in the figure below
be passed through an LTI system with frequency
response H(𝜔), as given in the figure belowThe Fourier series representation of the output is given as
Answer : Option C
Explaination / Solution:
Q3. 
In the following network, the switch is closed at t = 0- and the sampling starts from t = 0. The sampling frequency is 10 Hz.
The expression and the region of convergence of the z -transform of the sampled signal are
Answer : Option C
Explaination / Solution:
Q4. The period of the signal 
is
is
Answer : Option D
Explaination / Solution:
No Explaination.
Q5. Suppose that the modulating signal is 
and the carrier signal is 
, which one of the following is a conventional AM signal without over-modulation
and the carrier signal is , which one of the following is a conventional AM signal without over-modulation
Answer : Option C
Explaination / Solution:
No Explaination.
Q6. The system represented by the input-output relationship 
is
is
Answer : Option B
Explaination / Solution:
No Explaination.
Q7. Consider an angle modulated signal 
The average power of x(t) is
The average power of x(t) is
Answer : Option B
Explaination / Solution:
No Explaination.
Q8. At t = 0, the function f(t) = sint/t has
Answer : Option B
Explaination / Solution:
No Explaination.
Q9. If the scattering matrix [S ] of a two port network is 
then the network is
then the network is
Answer : Option C
Explaination / Solution:
Q10. x(t)is a positive rectangular pulse from t = −1 to t = +1 with unit height as shown in the figure. The value of 
{ where X(ω) is the Fourier transform of x(t)} is
{ where X(ω) is the Fourier transform of x(t)} is
Answer : Option D
Explaination / Solution:
No Explaination.
