Page 99 - Computer Science V2.0 Class 11

5. Which of the following is the correct expression for De Morgan's law?
a. A + B = (A + B)' b. A.B = (A.B)' c. (A + B)' = A' + B' d. (A + B)' = A' . B'
6. Which of the following is the correct expression for Associative law?
a. (a + b) . c = a + (b + c)
b. (a . b) + c = a . (b + c)
c. (a + b) + c = 1
d. (a + b) + c = a + (b + c)
7. Which of the following gates results in True when all inputs are True?
a. XOR b. NAND c. NOR d. XNOR
' '
8. According to Involution law, ((A) ) will result in:
a. A b. A ' c. 1 d. 0
9. Which of the following is the correct expression for Absorption law?
a. a + a ● b = b b. a + a ● b = a c. a + a + b = a d. a● a ● b = a

10. The Boolean algebra law a + 0 = a is one of the expressions for ____________.
a. Identity Property b. Absorption Law c. Distributive property d. Involution Law

B. State whether the following statements are True or False:
1. Any value complemented twice will result in 1. __________
2. If a boolean expression is False, its complement will be True. __________
3. A NAND accepts two inputs, complements them, and then applies AND operator. __________
4. XOR gate is one of the universal gates. __________
5. De Morgan's law applies to only those circuits that are created using universal gates. __________
6. A NOR gate is a combination of an OR gate and a NOT gate. __________
7. The expression A.A will always result in 1. __________
8. The expression A+A' will always result in 1. __________
9. An inverted (or complemented) XOR gate is called OR gate. __________
C. Fill in the blanks.
1. Boolean Algebra was developed by ________________.
2. The NOT gate takes only ____________ input.
3. Binary logic deals with operations on _____________ data.
4. In case of AND gate, the output will be ___________ if both inputs are 1.
5. ________ and __________ are universal gates.
6. A table that describes the result of applying an operator on each combination of values of the variables is called a
_______________.
7. The + symbol denotes __________ gate.
8. A' is called the ______________ of A.
9. _____________ gate has the effect of applying AND gate followed by NOT gate.
10. The ____________ gate is also known as the equivalence gate.

D. Answer the following:
1. Describe Boolean algebra of two elements and state the postulates of Boolean algebra.
2. Using truth tables verify the following laws of Boolean algebra:
a. Associative Law b. Distributive Law
3. Verify the following using Boolean expressions using truth tables.
a. A + C = A + A'.C + B.C [Delhi 2013]
b. X + Z = X + X'.Z + Y.Z [AI 2013]

Boolean Logic 85