Problems on Logic Gates

Most probably, we all heard about Burglar alarm.

It is a device that we used in our houses to protect it from thieves.

That alarm works on the logic of $A N D$ gate.

Means, when both the person sensor and Alarm sensor are $O N$ then the Burglar Alarm is activated.

And as the $A N D$ gate is one of the types of Logic gate.

Logic gates are useful to do logical operations in computer.

There are different types of logic gates.

Now, we will understand the logic gates by solving problems on it.

Let’s take a problem based on logic gates.

Suppose we have a circuit of a combination of $O R$ gate and $N A N D$ gate.

And the value of $A$ , $B$ and $C$ is zero.

Now, we need to find the value of output $D$ .

As the input of $O R$ gate is high when at least one input is high.

Here, the value of both input is low means $0$ .

So, by using the truth table, we can say that the output through $O R$ gate will be zero.

Now, the output through $O R$ gate and input $C$ is passed through $N A N D$ gate.

The output of $N A N D$ gate is high when at least one of the input is low or zero.

By using the truth table of $N A N D$ gate, we can say that the output through it is high or $1$ .

So, the output $D$ of the above question is high or $1$ .

When multiple logic gates are connected with wires.

Then, they will form a complex digital circuit like in this case.

So, Boolean algebra is useful to simplify these digital circuits.

And it helps in lower the cost and raise the speed and efficiency of digital circuits.

There are some rules of Boolean Algebra which we used to simplify any logical circuit.

Now, let’s try to understand these rules by using a problem.

Suppose we have an equation of logical gates as above

And we need to simplify it.

So, by using Boolean Algebra for $O R$ gate, we simplify the equation as above,

And for $A N D$ gate, we simplify the equation as above,

Hence, we can easily solve the problems based on logic gates.

Revision

Logic gates are useful to do logical operations in computer.

There are different types of logical gates.

Boolean algebra is useful to simplify complex digital circuits.

The End