# Use of components practically

Practically … ! you might be thinking well all the components in a product is used practically. Yes you are right, saying practically means we will learn about component example circuit so that we can also apply it practically. It will be cool . Merely studying books you will not be able to know the proper working of the components. So we will start from basic i.e. active and passive components.

## Passive Components –

Check out my previous post to get some idea about passive components. So, further we will start from very basic component and how we can use it in different ways in designing any product (this one is advance level).

### Resistors

Let’s make it easier for college buddies by providing some points.

### Explanation :

As we all know resistor is a passive a component and what it does is it acts as speed breaker on roads, or consider situation 1 you are running on free road with crowd at all, you will move or run very fast. Now 2nd situation, you are running on a crowded road. Yes you got it right in 2nd situation you will walk or run very slowly because your speed is limited.

In the same way primary function of resistor is to resist the flow of current through it.

In additional it can be used as:

• Voltage divider
• Current limiting
• Pull-up resistor
• Bias active elements
• Terminate transmission lines

### Derivation:

For using it in circuit it is obvious that it is to be connected in circuit first and there will be some voltage in circuit. So the relationship between  that Voltage, ( v ) Current, ( I) and some constant value Resistance, ( R ) would come up with a relation as below :

By going with the Ohm’s Law definition (you know already), Current directly proportional to the Voltage :

I ∝ V

where R comes out as a resistive constant here.

In the graph shown below , V – I graph relationship resulting in a slope which is the value of the resistor.