UGC NET Previous Year Papers

Computer Science – Paper II

December 2007

1.   A box contains six red balls and four green balls. Four balls are selected at random from the box. What is the probability that two of the selected balls are red and two are green?

(A)   \frac{3}{7}/ugc-net-previous-year-papers-computer-science-paper-ii-dec-2007              

(B)   \frac{4}{7}

(C)   \frac{5}{7}               

(D)   \frac{6}{7}

Ans: (A)


2. The number of edges in a complete graph with ‘n’ vertices is equal to:

(A) n(n-1)          

(B) \frac{n(n-1)}{2}

(C) n2                

(D) 2n-1

Ans: (B)


3. A context free grammar is:

(A) type 0          

(B) type 1

(C) type 2         

(D) type 3

Ans: (C)


4. Let e: B˄m→B˄n is a group code. The minimum distance of ‘e’ is equal to:

(A) the maximum weight of a non zero code word

(B) the minimum weight of a non zero code word

(C) m

(D) n

Ans: (B)


5. Consider a Moore Machine M whose digraph is:
Then L(M), the language accepted by the machine M, is the set of all strings having:

(A) two or more b’s     

(B) three or more b’s

(C) two or more a’s     

(D) three or more a’s

Ans: (A)


6. A WFF that is equivalent to the WFF x=>y is:

(A) y=>x            

(B) ~y=>x

(C) ~y=>~x       

(D) y=>~x

Ans: (B)


7. Simplified form of Boolean expression xy+(~x)z+yz is:

(A) xy+(~x)z     

(B) (~x)y+(~x)z

(C) (~x)y+xz     

(D) xy+xz

Ans: (A)


8. In order to build a MOD-18 counter, the minimum number of flip flops needed is equal to:

(A) 18    

(B) 9

(C) 5      

(D) 4

Ans: (C)


9. The dual of the switching function F=x+yz is given by:

(A) x+yz                        

(B) x(y+z)

(C) (~x)+(~y)(~z)          

(D) (~x)((~y)+(~z))

Ans: (B)


10. Amongst the logic families DTL, TTL, ECL and CMOS, the family with the least power dissipation is:

(A) CMOS        


(C) TTL             


Ans: (A)


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