INTRODUCTION SIGNAL & SYSTEM

1) Which mathematical notation specifies the condition of periodicity for a continuous time signal?

• a. x(t) = x(t +T0)
• b. x(n) = x(n+ N)
• c. x(t) = e-αt
• d. None of the above

2) Which property of delta function indicates the equality between the area under the product of function with shifted impulse and the value of function located at unit impulse instant?

• a. Replication
• b. Sampling
• c. Scaling
• d. Product

For a double sided function, which is odd, what will be the integral of the function from -infinity to +infinity equal to?

• A) Non-zero Finite
• B) Zero
• c. x(t) = e-αt
• d) None of the mentioned

Which of the following conditions made digital signal processing more advantageous over analog signal processing?

• a) Flexibility
• b) Accuracy
• c) Storage
• d) All of the mentioned

An amplitude of sinc function that passes through zero at multiple values of an independent variable ‘x’ 

• a. Decreases with an increase in the magnitude of an independent variable (x
• b. Increases with an increase in the magnitude of an independent variable (x)
• c. Always remains constant irrespective of variation in magnitude of ‘x’
• d. Cannot be defined

Which among the following are the stable discrete time systems?
1. y(n) = x(4n)
2. y(n) = x(-n)
3. y(n) = ax(n) + 8
4. y(n) = cos x(n)

• a. 1 & 3
• b. 2 & 4
• c. 1, 3 & 4
• d. 1, 2, 3 & 4

Which block of the discrete time systems requires memory in order to store the previous input?

• a. Adder
• b. Signal Multiplier
• c. Unit Delay
• d. Unit Advance

The interface between an analog signal and a digital processor is

• a. D/A converter
• b. A/D converter
• c. Modulator
• d. Demodulator

Telegraph signals are examples of

• Digital signals
• Analog signals
• Impulse signals
• Pulse train

The discrete impulse function is defined by

• a. δ(n) = 1, n ≥ 0 
  = 0, n ≠ 1
• b. δ(n) = 1, n = 0 
  = 0, n ≠ 1
• c. δ(n) = 1, n ≤ 0 
  = 0, n ≠ 1
• d. δ(n) = 1, n ≤ 0 
  = 0, n ≥ 1