Signals and Systems - Online Test

Q1.
The impedance looking into nodes 1 and 2 in the given circuit is

Answer : Option A
Explaination / Solution:




Q2. A band-limited signal with a maximum frequency of 5 kHz is to be sampled. According to the sampling theorem, the sampling frequency in kHz which is not valid is
Answer : Option A
Explaination / Solution:
No Explaination.


Q3. In the following figure, C1 and C2 are ideal capacitors. C1 has been charged to 12 V before the ideal switch S is closed at t = 0. The current i(t) for all t is 

Answer : Option D
Explaination / Solution:

Time constant = RC In the given circuit, R = 0 Rise time = 0; hence capacitor charges instantaneously and the current can be represented as impulse function

Q4. For a periodic signal  the fundamental frequency in radians/s is 
Answer : Option A
Explaination / Solution:
No Explaination.


Q5. The average power delivered to an impedance (4 - j3)Ω by a current 5cos(100πt +100) A is
Answer : Option B
Explaination / Solution:



Q6. A continuous random variable X has a probability density function  is
Answer : Option A
Explaination / Solution:
No Explaination.


Q7.
With 10 V dc connected at port A in the linear nonreciprocal two-port network shown below, the following were observed:
(i) 1Ω connected at port B draws a current of 3 A
(ii) 2.5Ω W connected at port B draws a current of 2 A 

For the same network, with 6 V dc connected at port A, 1Ω connected at port B draws 7/3 A. If 8 V dc is connected to port A, the open circuit voltage at port B is 
Answer : Option B
Explaination / Solution:
No Explaination.


Q8. Two systems with impulse responses h1(t) and h2(t) are connected in cascade. Then the overall impulse response of the cascaded system is given by 
Answer : Option C
Explaination / Solution:
No Explaination.


Q9.
With 10 V dc connected at port A in the linear nonreciprocal two-port network shown below, the following were observed:
(i) 1Ω connected at port B draws a current of 3 A
(ii) 2.5Ω W connected at port B draws a current of 2 A 
With 10 V dc connected at port A, the current drawn by 7 Ω connected at port B is
Answer : Option C
Explaination / Solution:
No Explaination.


Q10. The impulse response of a system is h(t) = tu(t). For an input u(t − 1), the output is
Answer : Option C
Explaination / Solution:
No Explaination.