A directory of Objective Type Questions covering all the Computer Science subjects. Here you can access and discuss Multiple choice questions and answers for various compitative exams and interviews.

31. The minimum number of JK flip-flops required to construct a synchronous counter with the count sequence (0, 0, 1, 1, 2, 2, 3, 3, 0, 0,...) is ________.
a. 0
b. 1
c. 2
d. 3
View Answer Report Discuss Too Difficult! Search Google
Answer: (d).3

32. The number of min-terms after minimizing the following Boolean expression is _________.

[D′ + AB′ + A′C + AC′D + A′C′D]′
a. 1
b. 2
c. 3
d. 4
View Answer Report Discuss Too Difficult! Search Google
Answer: (a).1

33. A half adder is implemented with XOR and AND gates. A full adder is implemented with two half adders and one OR gate. The propagation delay of an XOR gate is twice that of an AND/OR gate. The propagation delay of an AND/OR gate is 1.2 microseconds. A 4-bit ripple-carry binary adder is implemented by using full adders. The total propagation time of this 4-bit binary adder in microseconds is
a. 19.2 microseconds
b. 18.0 microseconds
c. 12.3 microseconds
d. 16.6 microseconds
View Answer Report Discuss Too Difficult! Search Google
Answer: (a).19.2 microseconds

34. The total number of prime implicants of the function f(w, x, y, z) = Σ(0, 2, 4, 5, 6, 10) is ________.
a. 2
b. 3
c. 4
d. 5
View Answer Report Discuss Too Difficult! Search Google
Answer: (b).3

35. Given the function F = P′ + QR, where F is a function in three Boolean variables P, Q and R and P′ = !P, consider the following statements.

S1: F = Σ (4, 5, 6)
S2: F = Σ (0, 1, 2, 3, 7)
S3: F = Π (4, 5, 6)
S4: F = Π (0, 1, 2, 3, 7)

Which of the following is true?
a. S1-False, S2-True, S3-True, S4-False
b. S1-True, S2-False, S3-False, S4-True
c. S1-False, S2-False, S3-True, S4-True
d. S1-True, S2-True, S3-False, S4-False
View Answer Report Discuss Too Difficult! Search Google
Answer: (a).S1-False, S2-True, S3-True, S4-False

36. What is the minimum number of NAND gates required to implement a 2-input EXCLUSIVE-OR function without using any other logic gate?
a. 3
b. 4
c. 5
d. 6
View Answer Report Discuss Too Difficult! Search Google
Answer: (b).4

37. Using a 4-bit 2’s complement arithmetic, which of the following additions will result in an overflow? (i) 1100 + 1100 (ii) 0011 + 0111 (iii) 1111 + 0111
a. (i) only
b. (ii) only
c. (iii) only
d. (i) and (iii) only
View Answer Report Discuss Too Difficult! Search Google
Answer: (b).(ii) only

38. The number (123456)8 is equivalent to
a. (A72E)16 and (22130232)4
b. (A72E)16 and (22131122)4
c. (A73E)16 and (22130232)4
d. (A62E)16 and (22120232)4
View Answer Report Discuss Too Difficult! Search Google
Answer: (a).(A72E)16 and (22130232)4

39. The function AB’C + A’BC + ABC’ + A’B’C + AB’C’ is equivalent to
a. AC’+AB+A’C
b. AB’+AC’+A’C
c. A’B+AC’+AB'
d. A’B+AC+AB'
View Answer Report Discuss Too Difficult! Search Google
Answer: (b).AB’+AC’+A’C

40. Which of the following expressions is equivalent to (A⊕B)⊕C
a. (A+B+C)(A¯+B¯+C¯)
b. (A+B+C)(A¯+B¯+C)
c. ABC+A¯(B⊕C)+B¯(A⊕C)
d. None of the above
View Answer Report Discuss Too Difficult! Search Google
Answer: (c).ABC+A¯(B⊕C)+B¯(A⊕C)

Page 4 of 10