# Verification of logic gates experiment | Lab Work

## Aim : Verification of Logic Gates.

#### Components Required

Components required for verification of logic gates are –

1) IC 7404 Hex inverter ( NOT Gate )

2) IC 7408 ( AND Gate )

3) TC 7432 ( OR Gate )

4) IC 7486 ( XOR Grate )

5) IC 7402 ( NOR Gate )

6) IC 7400 ( NAND Gate )

7) Electronic trainer bound

8) Connecting wires

#### Theory

These are the fundamental building blocks of the digital system. It produces one output level I when some combination of input levels is present. The three basic types of logic gates AND, OR and NOT Gate. A table which lists all variable inputs and corresponding output is called truth table. The variables are binary, logic 1 is designated as ON or High State. Whereas logic 0 as off Low state.

### NOT Gate ( IC 7404 )

A NOT gate is also known as inverter. It has one input and one output. Its output is complemented of its input.

Truth table for NOT Gate

 Input Output 1 0 0 1

#### IC 7404 Pinout ### AND Gate ( IC 7408 )

An AND Gate has two or more inputs but only one output. The output assumes logic 1 state, only when all of its input is at logic 1 state. The output assumes the logic 0 state even if one of its inputs is at logic 0 state.

Truth Table for AND Gate

 Input A Input B Output Y 0 0 0 0 1 0 1 1 1 1 0 0

#### IC 7408 Pinout ### OR Gate ( IC 7432 )

The OR Gate may have two or more inputs and only output. The output assumes the logic 1 state, even if one of its inputs is at logic 1 state. Its output assumes logic O state, only when each of its input logic 0 state.

Truth table for OR Gate

 Input A Input B Output Y 0 0 0 0 1 1 1 1 1 1 0 1

#### IC 7432 Pinout ### NOR Gate ( IC 7402 )

NOR means NOT + OR, so a NOR Gate is a combination of an OR Gate and NOT Gate. The output is at logic 1 state, only when each of its input are any in logic 0 level for other combination of inputs, the output is at logic zero state. It is a universal gate.

Truth table for NOR Gate

 Input A Input B Output Y 0 0 1 0 1 0 1 1 0 1 0 0

#### IC 7402 Pinout ### NAND Gate ( IC 7400 )

NAND means NOT + AND, so a NAND Grate is a combination of an AND Gate and NOT Gate. The Output logic zero state only when all of its input is in logic 1 level. any for other combination of inputs the output of NAND Gate is at logic 1 level. It is a Universal gate.

Truth table for NAND Gate

 Input A Input B Output Y 0 0 1 0 1 1 1 1 0 1 0 1

#### IC 7400 Pinout ### XOR Gate ( IC 7486 )

The EX-OR operation is widely used in digital circuits. When both the input is in same logic state ( 0 or 1 ) the output of EX-OR is in logic 0 state, whereas when the inputs are not in same logic state i.e., if one of them is zero and the other is 1 the output is in logic 1 state.

Truth table for NAND Gate

 Input A Input B Output Y 0 0 0 0 1 1 1 1 0 1 0 1

#### IC 7486 Pinout ### Procedure

1. Fix the IC on the trainer board.
2. Carry out the connections and setting.
3. 5v dc supply was applied to pin no. 14 where as pin 7 was connected to common terminal ground.
4. Logic inputs are applied to input terminal whereas outputs were taken from the corresponding outputs. output probs logic 1 through set input & logic 0 through clear input. For output, red LED implies logic 1 & green led implies logic 0.
5. Similarly, all gates of on IC are green LED.

The result of the gates was verified according to the truth table of the corresponding gates.

#### Result & Conclusion

The result of all gates as observed was in accordance with their respective truth table, describing their behaviour.

#### Precaution

1. All the pins of on IC should be checked before using.
2. IC should be properly fixed. on trainer board and power supply to the pin 14 should not exceed from 5v dc.
3. Connection should be made tightly.
4. Power supply should be given to the trains board only after connections are made.
5. Insulation in connection should be avoided.

Author

Akash Sharma

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