# IIR System Structures

This set of Digital Signal Processing Multiple Choice Questions & Answers (MCQs) focuses on “Structures for IIR Systems”.

1. If M and N are the orders of numerator and denominator of rational system function respectively, then how many multiplications are required in direct form-I realization of that IIR filter?
a) M+N-1
b) M+N
c) M+N+1
d) M+N+2

2. If M and N are the orders of numerator and denominator of rational system function respectively, then how many additions are required in direct form-I realization of that IIR filter?
a) M+N-1
b) M+N
c) M+N+1
d) M+N+2

3. If M and N are the orders of numerator and denominator of rational system function respectively, then how many memory locations are required in direct form-I realization of that IIR filter?
a) M+N+1
b) M+N
c) M+N-1
d) M+N-2

4. In direct form-I realization, all-pole system is placed before the all-zero system.
a) True
b) False

5. If M and N are the orders of numerator and denominator of rational system function respectively, then how many memory locations are required in direct form-II realization of that IIR filter?
a) M+N+1
b) M+N
c) Min [M,N]
d) Max [M,N]

6. The basic elements of a flow graph are branches and nodes.
a) True
b) False

7. Which of the following is true for the given signal flow graph?

a) Two pole system
b) Two zero system
c) Two pole and two zero system
d) None of the mentioned

8. What are the nodes that replace the adders in the signal flow graphs?
a) Source node
b) Sink node
c) Branch node
d) Summing node

9. The output signal of a system is extracted at a sink node.
a) True
b) False

10. If we reverse the directions of all branch transmittances and interchange the input and output in the flow graph, then the resulting structure is called as ______________
a) Direct form-I
b) Transposed form
c) Direct form-II
d) None of the mentioned

11. What does the structure given below represents?

a) Direct form-I
b) Regular Direct form-II
c) Transposed direct form-II
d) None of the mentioned

12. The structure shown below is known as ____________

a) Parallel form structure
b) Cascade structure
c) Direct form
d) None of the mentioned