CLASS-XI COMPUTER SCIENCE CHAPTER-3 ASSIGNMENT SOLUTION
1. Verify using truth table that X + XY = X for each X, Y in {0,1}
| X | Y | XY | X+XY |
| 0 | 0 | 0 | 0 |
| 0 | 1 | 0 | 0 |
| 1 | 0 | 0 | 1 |
| 1 | 1 | 1 | 1 |
2. Verify using truth table that \( \overline{(X + Y)} \) = \( \overline{X}\overline{Y}\) for each X, Y in {0,1}
| X | Y | X+Y | \( \overline{(X+Y)} \) | \( \overline{X} \) | \( \overline{Y} \) | \( \overline{X}.\overline{Y} \) |
| 0 | 0 | 0 | 1 | 1 | 1 | 1 |
| 0 | 1 | 1 | 0 | 1 | 0 | 0 |
| 1 | 0 | 1 | 0 | 0 | 1 | 0 |
| 1 | 1 | 1 | 0 | 0 | 0 | 0 |
3. Give truth table for the Boolean expression: \( \overline{(X+\overline{Y})} \).
| X | Y | Y’ | \( X+\overline{Y} \) | \( \overline{(X+\overline{Y})} \) |
| 0 | 0 | 1 | 1 | 0 |
| 0 | 1 | 0 | 0 | 1 |
| 1 | 0 | 1 | 1 | 0 |
| 1 | 1 | 0 | 1 | 0 |
4. Draw truth table for the following equations:
(a) M = N (P+R)
| N | P | R | P+R | N (P+R) |
| 0 | 0 | 0 | 0 | 0 |
| 0 | 0 | 1 | 1 | 0 |
| 0 | 1 | 0 | 1 | 0 |
| 0 | 1 | 1 | 1 | 0 |
| 1 | 0 | 0 | 0 | 0 |
| 1 | 0 | 1 | 1 | 1 |
| 1 | 1 | 0 | 1 | 1 |
| 1 | 1 | 1 | 1 | 1 |
(b) M = N+P+NP̄
| N | P | R | P̄ | NP̄ | N+P+NP̄ |
| 0 | 0 | 0 | 1 | 0 | 0 |
| 0 | 0 | 1 | 1 | 0 | 0 |
| 0 | 1 | 0 | 0 | 0 | 1 |
| 0 | 1 | 1 | 0 | 0 | 1 |
| 1 | 0 | 0 | 1 | 1 | 1 |
| 1 | 0 | 1 | 1 | 1 | 1 |
| 1 | 1 | 0 | 0 | 0 | 1 |
| 1 | 1 | 1 | 0 | 0 | 1 |
5. Using truth table, prove that: AB+BC+C= AB+CĀ
| A | B | C | Ā | AB | BC | CĀ | AB+CB+C | AB+CĀ |
| 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
| 0 | 0 | 1 | 1 | 0 | 0 | 1 | 1 | 1 |
| 0 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
| 0 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 |
| 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 1 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| 1 | 1 | 0 | 0 | 1 | 0 | 0 | 1 | 1 |
| 1 | 1 | 1 | 0 | 1 | 1 | 0 | 1 | 1 |
6. State the principal of duality in boolean algebra and give the dual of the boolean expression.
(X+Y).( X’+Z’).(Y+Z)
According to the principle of duality, a true boolean statement or expression can be converted to its dual form by replacing the “0”s in the statement or expression with “1”s, and vice versa and by replacing the “+”s in the statement or expression with “.”s, and vice versa.
The dual form of (X+Y)(X’+Z’ ).(Y + Z) is (X.Y)+(X’.Z’ )+(Y.Z)
In the above dual expression all the “+”s were replaced by “.”s, and vice versa.
7. Prove the idempotence law of boolean algebra with the help of a truth table
| X | X | Output X.X | X+X |
| 0 | 0 | 0 | 0 |
| 1 | 1 | 1 | 1 |
Continue….
Tag:Computer Science, CS, XI
