Question

The impulse response of an discrete time LTI system is given by
$h\left[n\right]=3\delta [n-1]+2\delta [n-2]+\delta [n-3]$
The value of $H\left(z\right)$ at $z=1$ is

• A.
  6
• B. 3
• C. 2
• D. 1

Answer 1

The correct option is A

6
$h\left[n\right]=3\delta [n-1]+2\delta [n-2]+\delta [n-3]$

$H\left(z\right)=3Z^{-1}+2Z^{-2}+Z^{-3}$

$H\left(1\right)=3\times 1+2\times 1+1=6$