In the linear feedback shift register used to produce pseudo-random patterns, the patterns are deterministically generated and are repeatable.
12. Primitive polynomial should have a minimum number of zero coefficients.
A. true
B. false
Answer: A
Primitive polynomials with a minimum number of zero coefficients are the desired characteristic polynomial for the LFSR.
13. The minimum number of EX-OR gates used is in between
A. 0 to 2
B. 1 to 3
C. 2 to 5
D. 3 to 7
Answer: B
The minimum number of EX-OR gates used for the linear feedback shift register is between 1 and 3.
14. The LFSR takes reasonable time if the n value is
A. below 50
B. below 100
C. below 10
D. below 25
Answer: D
The LFSR’s degree value is limited to 22 to 25 for producing maximal length sequence in a reasonable amount of time.
15. Which is used to initialize the LFSRs?
A. zeroes
B. ones
C. preset of flip-flop
D. EX-OR gate
Answer: C
The preset of each flip-flop in LFSR to used to initialize the LFSRs and the initial non-zero coefficient or state ensures maximal length sequence is obtained.
16. The beginning and end of the maximal length sequence can be determined using
A. AND gate
B. NAND gate
C. AND or NAND gate
D. Both AND and NAND gate
Answer: C
The beginning and end of the maximal length sequence of the LFSR can be determined using AND gate or NAND gate.
17. Preloading different starting values for the LFSR is called as
A. seeding
B. reseeding
C. deseeding
D. pre-seeding
Answer: B
Initializing with a specific value to the LFSR is called as seeding and preloading different starting value is called reseeding.
18. The primitive polynomial has a property according to which the runs of 1s ______ to runs of 0s.
A. equal
B. greater
C. lesser
D. not related
Answer: A
The primitive polynomial has a property of randomness according to which the runs of are equal to runs of 0s.
19. The total number of runs is given mathematically as
A. 2n
B. 2(n-1)
C. 2(n+1)
D. 2n-1
Answer: B
The total number of runs is given as 2(n-1) which is the total number of transitions from 1 to 0 or from 0 to 1.
20. ______ of the runs will have a length of 1.
A. one third
B. one fourth
C. half
D. one eight
Answer: C
The length of the runs is distributed as – half of the runs have length 1, a quarter with length 2, an eight-length 3 and a sixteenth length 4, and so on.
