# Discrete Time Signals

This set of Digital Signal Processing Multiple Choice Questions & Answers (MCQs) focuses on ” Discrete Time Signals”.

1. 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

2. The discrete time function defined as u(n)=n for n≥0;u(n)=0 for n<0 is an _____________
a) Unit sample signal
b) Unit step signal
c) Unit ramp signal
d) None of the mentioned

3. The phase function of a discrete time signal x(n)=an, where a=r.e is?
a) tan(nθ)
b) nθ
c) tan-1(nθ)
d) none of the mentioned

4. The signal given by the equation ∑∞n=−∞|x(n)|2 is known as __________
a) Energy signal
b) Power signal
c) Work done signal
d) None of the mentioned

5. x(n)*δ(n-k)=?
a) x(n)
b) x(k)
c) x(k)*δ(n-k)
d) x(k)*δ(k)

6. 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

7. 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))

8. Time scaling operation is also known as ___________
a) Down-sampling
b) Up-sampling
c) Sampling
d) None of the mentioned

9. What is the condition for a signal x(n)=Brn where r=eαT to be called as an decaying exponential signal?
a) 0<r<∞
b) 0<r<1
c) r>1
d) r<0

10. The function given by the equation x(n)=1, for n=0; x(n)=0, for n≠0 is a _____________
a) Step function
b) Ramp function
c) Triangular function
d) Impulse function