# Logical gates and Boolean Laws questions

## Short answer questions (1 mark)

### Fill in the blanks:

- A __________ statement returns either True or False value.
- The logical values can be stored in ______________.
- A __________ represents a Boolean function with all the input and output in tabular form.
- The only boolean function which operate on a single input variable is ____________.
- The _____________ is a boolean operation which perform multiplication.
- The ___________ is a boolean operation which perform addition.
- The boolean expression evaluated from ________ to ___________.
- The _________ operator has high (top) priority in boolean statement evaluation.
- The __________ is a graphical representation of turth table.
- The __________ gate produces the reverse result of AND gate.

### Answers:

- boolean
- logical variables or constants
- Truth Table
- Not
- AND
- OR
- left, right
- NOT
- Logical Gate
- NAND

### Assignment Chapter 1

### MCQs:

- When the result of any boolean statement is always 1 is known as ___________.

- True
- Tautology/
- Fallacy
- False

- When the result of any boolean statement is always 0 is known as ______________.

- True
- Tautology
- Fallacy
- False

- The logical operations can be carried out by which of the following?

- Values and Variables
- Functions and Laws
- Operators and Operands
- None of these

- To denote NOT operation which of the following symbols is used?

- bar
- dot
- plus
- asterisk

- The dot symbol is used to represent which of the following operation?

- AND
- OR
- NOT
- NAND

- Which of the following are logical statements:

- The Indian cricket team is a world champion in 2011.
- What are the parts of the boolean function?
- There are three types of boolean operators.
- The NOT function can be operated on more than one Boolean function.

- Which of the following gate is also known as an invertor

- AND
- OR
- NOT
- NAND

- Which of the following gate returns a true result if both inputs are true otherwise false.

- AND
- OR
- NOT
- None of the above

- Which gate can be written like A & B

- AND
- OR
- NOT
- XOR

- Which gate returns true if both inputs are similar otherwise false.

- NAND
- NOR
- XOR
- None of the above

### Answers:

1. b.Tautology 2. c. Fallcy 3. c. Operators and Operands 4. a. bar 5. a. AND

6. a and d 7. c. NOT 8. a. AND 9. a. AND 10. XOR

## Descriptive questions:(2/3 marks)

- Prepare the truth table for a. X+(X.Y) b. X.(X+Y) c. X + Y d. (X.Y) + (Y.X)
- Write rules for preparing the truth table.
- Explain the following gates with an example:
- AND
- OR
- NAND
- NOR
- XOR
- Name following law and verify them using a truth table:
- x + x’ = 1
- x + y = y + x
- x + (y + z ) = (x + y ) + z
- x + xy = x
- (x + y)’ = x’.y’
- Draw logical circuits for following:
- Y = ab + bc + ca
- Y = (a+b)’ . (a+b)
- Y = a’.b’ + (a.b)’
- Prove DeMorgan’s law using truth table.
- Draw the logic circuit of boolean expression using NAND gate: (A.B)+ (C.D)
- Represent the boolean expression A’B+B’C using the NAND gate.
- Draw the logical circuit of F(x,y,z) = (x + y’) (y + z’) using NOR gate.
- State and verify involution law.