Ohm's Law

Ohms Law

Video Link

Ohm is very small unit but it is very important for electronics

Ohm is the unit of resistance

In our previous video we discussed about the resistance

To clear the resistance topic we must understand that where we can find resistance and practically what is the resistance

In our previous video we saw that

Resistor is a passive component; it is only theoretically we studied

But practically everything has own resistance and it is also important for conduction also

Yes

Resistance is also important for conduction

How ?

Ok let’s see

Just take a small piece of wire and check its resistance and take another long piece of wire and also check it’s resistance you will get some small resistance value in small piece of wire and large resistance value on long piece of wire in comparison with small piece

But a wire can conduct electricity even resistance is present in the wire

You can just do this through multimeter

My motive is only that you should understand everything has its own resistance which opposes the flow of current to the some extent

Ok

Now we have to come on our topic Ohm’s law

Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points.

 I = V / R

where I is the current through the conductor in units of amperes, V is the voltage measured across the conductor in units of volts, and R is the resistance of the conductor in units of ohms. More specifically, Ohm's law states that the R in this relation is constant, independent of the current

it is the symbol of ohm

The law was named after the German physicist Georg Ohm, who, in a treatise published in 1827,

For understanding the ohms law equations this is very important to remember this triangle

To clear more this triangle

1^st if we have to calculate voltage of any given circuit than your formula will be

your formula will be

V = I X R

2^nd if we have to calculate Current of any given circuit than your formula will be

your formula will be

I = V / R

3^nd if we have to calculate Resistance of any given circuit than your formula will be

your formula will be

R = V / I

For example

Here we have to calculate resistance value for this circuit

1^st observe what you have to require for calculating the resistance

Formula :-  R = V / I

Here we required the data of green LED

Suppose green led requires = 3 volt and 0.10 A current

For calculating resistance

Here we have voltage (v = 9-3 = 6 v)

Current = 0.10 ampere

R = 6/0.10 = 60 ohm

Here we calculated resistance value 60 ohm

But practically we have to know that which watt of resistance is used here because resistors are categorized with 1 / 4 watt (quarter watt), 1 / 2 watt (half watt), 1 watt (one watt) as on

we know that unit of power is watt

Power = volt X ampere

Here we have = 9 volt supply and 0.10 ampere current

Power = 0.9 watt

Approx 1 watt

And 1 to 25 watt requires (1 / 4 watt resistor)

26 to 50 watt requires ( 1 / 2 watt resistor ) as on

This is the basic tutorial about ohms law and their calculations 

Thank you

Resistor

Resistor Basic (Link)

Hear we discuss about the basic electronics components like resistors capacitors inductors as on.

our motive is to just clear the basic concept of electronics components what they actually works and we will discuss in detail in our further videos

But in this video we discuss about the Resistors

1st

What is Resistor?

In short we can say that

A resistor is a passive component and the basic work of a resistor is to oppose the flow of current.

because the resistance is inversely proportional to the current

R=1 / i

that means when the resistance value is low than the current will be higher

and when the resistance will be higher than the current will be lower

according to above definition we have to understand two words which comes in above definition

1st is Passive component and 2nd Current

passive components are those components which consumes power

and we know that power is equals to voltage multiplied by ampear

P = V x A

ampear is the unit of current

and resistor opposes the flow of current which effects the resultant power

Symbols of Resistor

according to symbol it is clear that resistors have no polarity

polarity means it has no positive or negative poles

so it does not matters from which side component will connect in the circuit

There are basically two types of resistor

1st is fixed type

and

2nd is variable type

fixed type resistors are those type of resistors whose value is fixed it can't be changed by us

like carbon film metal film etc are fixed type resistors

and

variable type resistors are those resistors whose value may be changed by ourselves

like potentiometer

potentiometer also called pot resistor or presets as in our general language

the pot resistors are mostly used for controlling the volume of a device , brightness or contrast  of display etc that means where we have to control the gain for desirable output

for obtaining the value of resistor in any given electronics circuit  we have to understand ohm's law

and

we will discuss ohm's Law in our next video

Thank you