Page 93 - ComputerScience_Class_11

2. NAND gate is formed by the combinations of ………………… .
a. AND gate and OR gate b. OR gate and NOT gate
c. NAND gate and NOT gate d. AND gate and NOT gate
3. The proposition ∼(a ∧ b) ∨ (∼a → b) is a ………………… .
a. contradiction b. contingency
c. tautology d. implication
4. Which of the following is a negated AND gate?
a. NAND b. NOR
c. XOR d. XNOR
5. What is the contrapositive of conditional a' → b?
a. a → b' b. a → b
c. b → a' d. b' → a
6. Which of the following symbol represents XOR operation?
a. ∨ b. ∧
c. ⊕ d. ⊙
7. A ………………… is a proposition which has 1 as its truth value.
a. conditional b. tautology
c. biconditional d. contradiction
8. Which of the following is the symbol of equivalence?
a. → b. ⇒
c. ⊃ d. None of these
9. Let, P: It is raining outside, Q: You should go out and play.
Then “It is raining outside and you should not go out and play” – is best represented by ………………… .
a. ∼P ∨ ∼Q b. P ∨ ∼Q
c. P ∧ ~Q d. P ∧ Q
10. The propositions used to draw conclusions are called ………………… .
a. syllogism b. premises
c. contradiction d. equivalence
B. Fill in the blanks.

1. The Boolean expression of two variables XNOR gate represented by variables A and B is ………………… .
2. The gate produced by combining two NOR gates in a series is ………………… .
3. ………………… is the expression of the sum term of a half adder.
4. AND, OR, NOT are called ………………… gates.
5. XOR gate produces 1 for ………………… combinations of 1 as input.
6. ………………… is pronounced as exclusive OR gate.
7. The ………………… gate produces 1 as output when all its inputs are 1.
8. AND gate is 1 when ………………… its inputs are 1.
9. When the antecedent and consequent of a proposition are interchanged, the resulting proposition is called ………………… .
10. The carry term of a full adder is ………………… .
C. Answer the following questions:
1. Distinguish between:
a. Simple proposition and compound proposition
b. Conjunction and disjunction
c. Conditional and biconditional
d. AND gate and OR gate
e. Half adder and full adder
2. Consider the following propositions:
P = “It is raining heavily”

Propositional Logic, Hardware Implementation, Arithmetic Operations 91