Logic-Gates

Question 1
Let and denote the Exclusive OR and Exclusive NOR operations, respectively. Which one of the following is NOT CORRECT?
A
B
C
D
       Digital-Logic-Design       Logic-Gates       Gate 2018
Question 1 Explanation: 
Question 2
Which one of the following circuits is NOT equivalent to a 2-input XNOR (exclusive NOR) gate?
A
B
C
D
       Digital-Logic-Design       Logic-Gates       Gate 2011
Question 2 Explanation: 
All options except option ‘D’ gives EX-NOR gates
Question 3
 
A
B
C
D
       Digital-Logic-Design       Logic-Gates       2010
Question 3 Explanation: 
f = ((P’Q’ + Q’R’)’ + ( P’R’ + Q’R’)’ )’
= (P’Q’ + Q’R’)( P’R’ + Q’R’)
= (P’Q’P’R’ + P’Q’Q’R’ + Q’R’P’R’ + Q’R’Q’R’)
= (P’Q’R’ + P’Q’R’ + P’Q’R’ + Q’R’)
= (P’Q’R’ + Q’R’)
= (Q’R’)
= (Q+R)’
Question 4
What is the minimum number of gates required to implement the Boolean function (AB+C) if we have to use only 2-input NOR gates?
A
2
B
3
C
4
D
5
       Digital-Logic-Design       Logic-Gates       2009
Question 4 Explanation: 
NOR is Complement of OR
AB+C
= (A+C)(B+C) ← Distribution of + over
= ((A+C)’+(B+C)’)’
1st NOR- (A+C)’. Let X = (A+C)’
2nd NOR- (B+C)’. Let Y = (B+C)’
3rd NOR- (X+Y)’
Question 5
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
       Digital-Logic-Design       Logic-Gates       Gate 2004-IT
Question 5 Explanation: 

To create 2-input Exclusive-OR function we require 4 NAND gates.
Question 6
 
A
1
B
2
C
3
D
4
       Digital-Logic-Design       Logic-Gates       Gate-2003
Question 6 Explanation: 

⇒ a will always be equal to A.
Question 7
   
A
x NAND X
B
x NOR x
C
x NAND 1
D
x NOR 1
       Digital-Logic-Design       Logic-Gates       Gate-1999
Question 7 Explanation: 
Question 8
 
A
A = 0, B = 0, C = 1
B
A = 0, B = 1, C = 1
C
A = 1, B = 0, C = 1
D
A = 1, B = 1, C = 1
       Database-Management-System       Logic-Gates       Gate-1999
Question 8 Explanation: 

So the above equation is satisfied if either C=0 or A=0 and B=1.
Hence, Option (B) is correct.
Question 9
Which of the following operations is commutative but not associative?
A
AND
B
OR
C
NAND
D
EXOR
       Digital-Logic-Design       Logic-Gates       Gate-1998
Question 9 Explanation: 
NAND operation is commutative but not associative.
Question 10
 
A
B
C
D
E
None of the above.
       Digital-Logic-Design       Logic-Gates       Gate-1994
Question 10 Explanation: 
Question 11
 
A
exclusive OR
B
exclusive NOR
C
NAND
D
NOR
E
None of the above
       Digital-Logic-Design       Logic-Gates       Gate-1993
Question 11 Explanation: 

So finally, we can write
There are 11 questions to complete.