Questions: Answer the following multiple choice questions.
Q1. The discrete time function defined as u(n) = n for n ≥ 0; = 0 for n < 0 is an:
a) Unit sample signal
b) Unit step signal
c) Unit ramp signal
d) None of the mentioned
Q2. The signal given by the equation
∞
∑ |x(n)|2
-∞
is known as:
a) Energy signal
b) Power signal
c) Work done signal
d) None of the mentioned
Q3. A real valued signal x(n) is called as anti-symmetric if:
a) x(n) = x(-n)
b) x(n) = -x(-n)
c) x(n) = -x(n)
d) None of the mentioned
Q4. Time scaling operation is also known as:
a) Down-sampling
b) Up-sampling
c) Sampling
d) None of the mentioned
Q5. The function given by the equation x(n)=1, for n=0;=0, for n≠0 is a:
a) Step function
b) Ramp function
c) Triangular function
d) Impulse function
Q6. If x(n) is a discrete-time signal, then the value of x(n) at non integer value of ‘n' is:
a) Zero
b) Positive
c) Negative
d) Not defined
Q7. The phase function of a discrete time signal x(n)=an, where a = r.ejθ is:
a) tan(nθ)
b) nθ
c) tan-1(nθ)
d) None of the mentioned
Q8. x(n)*δ(n-k)=?
a) x(n)
b) x(k)
c) x(k)*δ(n-k)
d) x(k)*δ(k)
Q9. The odd part of a signal x(t) is:
a) x(t)+x(-t)
b) x(t)-x(-t)
c) (1/2)*(x(t)+x(-t))
d) (1/2)*(x(t)-x(-t))
Q10. What is the condition for a signal x(n) = Brn where r = eαT to be called as an decaying exponential signal?
a) 0b) 0c) r>1
d) r<0