# UGC NET Computer Science Solved Paper II December 2006 - Part 1

1.       Which of the regular expressions corresponds to this grammar ?
S → AB / AS, A → a / aA, B → b
(A) aa*b+           (B) aa*b
(C) (ab)*             (D) a(ab)*
2.       The proposition ~qp is equivalent to:
(A)          (B)       (C)      (D)
3.       The number of edges in a complete graph with N vertices is equal to:
(A) N(N−1)        (B) 2N−1
(C) N−1              (D) N(N−1)/2
4.       Which of the following is not true ?
(A)
(B) A−B = A∩~B
(C)
(D)
5.       If (a2−b2) is a prime number where a and bϵN, then:
(A) a2−b2 = 3                 (B) a2−b2 = a−b
(C) a2−b2 = a+b             (D) a2−b2 = 5

6.       The hexadecimal equivalent of (10111)2×(1110)2 is:
(A) 150               (B) 241
(C) 142              (D) 101011110
7.       An example of a self complementing code is:
(A) 8421 code               (B) Gray code
(C) Excess-3 code       (D) 7421 code
8.       A sum of products expression can be implemented with...............logic gates.
(A) AND – OR              (B) NAND − OR
(C) AND – NOT            (D) OR – AND
9.       The characteristic equation of the D flip-flop is:
(A) Qn+1 = D       (B) Q = D
(C) Q = 1            (D) Q = 0
10.    Which of the following logic is the fastest ?
(A) RTL              (B) ECL          (C) HTL          (D) HCL
1. 1. 