| 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 ________. |
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Answer: (d).3
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| 32. | The number of min-terms after minimizing the following Boolean expression is _________. [D′ + AB′ + A′C + AC′D + A′C′D]′ |
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Answer: (a).1
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| 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 |
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Answer: (a).19.2 microseconds
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| 34. | The total number of prime implicants of the function f(w, x, y, z) = Σ(0, 2, 4, 5, 6, 10) is ________. |
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Answer: (b).3
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| 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? |
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Answer: (a).S1-False, S2-True, S3-True, S4-False
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| 36. | What is the minimum number of NAND gates required to implement a 2-input EXCLUSIVE-OR function without using any other logic gate? |
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Answer: (b).4
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| 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 |
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Answer: (b).(ii) only
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| 38. | The number (123456)8 is equivalent to |
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Answer: (a).(A72E)16 and (22130232)4
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| 39. | The function AB’C + A’BC + ABC’ + A’B’C + AB’C’ is equivalent to |
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Answer: (b).AB’+AC’+A’C
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| 40. | Which of the following expressions is equivalent to (A⊕B)⊕C |
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Answer: (c).ABC+A¯(B⊕C)+B¯(A⊕C)
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