41. 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
Answer: D
The summing node is the node that is used in the signal flow graph which replaces the adder in the structure of a filter.
42. The output signal of a system is extracted at a sink node.
A. True
B. False
Answer: A
The input to a system originates at a source node and the output signal is extracted at a sink node.
43. 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 _______
A. Direct form-I
B. Transposed form
C. Direct form-II
D. None of the mentioned
Answer: B
According to the transposition or flow-graph reversal theorem, if we reverse the directions of all branch transmittances and interchange the input and output in the flow graph, then the system remains unchanged. The resulting structure is known as transposed structure or transposed form.
44. What does the structure given below represent?
A. Direct form-I
B. Regular Direct form-II
C. Transposed direct form-II
D. None of the mentioned
Answer: C
The structure given in the question is the transposed direct form-II structure of a two-pole and two zero IIR systems.
45. The structure shown below is known as ________
A. Parallel form structure
B. Cascade structure
C. Direct form
D. None of the mentioned
Answer: A
From the given figure, it consists of a parallel bank of single-pole filters and thus it is called a parallel form structure.
46. The state-space or the internal description of the system still involves a relationship between the input and output signals, what is the additional set of variables it also involves?
A. System variables
B. Location variables
C. State variables
D. None of the mentioned
Answer: C
Although the state space or the internal description of the system still involves a relationship between the input and output signals, it also involves an additional set of variables, called State variables.
47. State variables provide information about all the internal signals in the system.
A. True
B. False
Answer: A
The state variables provide information about all the internal signals in the system. As a result, the state-space description provides a more detailed description of the system than the input-output description.
48. Which of the following gives the complete definition of the state of a system at time n0?
A. Amount of information at n0 determines output signal for n≥n0
B. Input signal x(n) for n≥n0 determines output signal for n≥n0
C. Input signal x(n) for n≥0 determines output signal for n≥n0
D. Amount of information at n0+input signal x(n) for n≥n0 determines output signal for n≥n0
Answer: D
We define the state of a system at time n0 as the amount of information that must be provided at time n0, which, together with the input signal x(n) for n≥n0 determines the output signal for n≥n0.
49. From the definition of the state of a system, the system consists of only one component called the memoryless component.
A. True
B. False
Answer: B
According to the definition of the state of a system, the system consists of two components called the memory component and memory less component.
50. If we interchange the rows and columns of the matrix F, then the system is called as __________
A. Identity system
B. Diagonal system
C. Transposed system
D. None of the mentioned
Answer: C
The transpose of the matrix F is obtained by interchanging its rows and columns, and it is denoted by FT. The system thus obtained is known as Transposed system.
