OHM'S LAW,VOLTAGE & CURRENT DIVISION RULE,SOURCE CONVERSION

OHM'S LAW,VOLTAGE & CURRENT DIVISION RULE,SOURCE CONVERSION

OHM’S LAW:-  
Ohm's law states that, “In any circuit Applied voltage of that circuit is directly proportional to the flow of current in that circuit”. 
i.e.,    V∞I

                               

Here, ‘R’ is taken as a constant.

In general, V=I∙R is also known as “Ohm’s law”.

 

Condition for applying Ohm’s law:-

Ohm’s law is applicable for only that circuit having one voltage source and one resistance or equivalent resistance. i.e.,  

           

Note:- If a circuit containing current source, then we first convert it in voltage source. After that conversion, we can use Ohm’s law. And also circuit containing no. of resistances then we have to first find its equivalent resistance.

VOLTAGE DIVISION RULE:-

Voltage division rule is applied on a circuit for finding individual voltage of an element or a resistance.

Formula:-

                            
Suppose that, three resistances ‘R₁’, ‘R₂’ & ‘R₃’ are connected in series with a voltage source ‘v’. So, the

Individual voltages ‘V₁’, ‘V₂’ & ‘V₃’ are given by,

In general,

Note:- voltage division rule is only applicable for that circuit in which resistances are in series with a battery source.

CURRENT DIVISION RULE:-

Current division rule is applied on a circuit for finding individual current of an element or a resistance.

Formula:-

 

Suppose that, two resistances ‘R₁’ & ‘R₂’   are connected in parallel with a current source ‘I’. So, the

Individual current ‘i₁’ & ‘i₂’ are given by,

In general,

Note:- Current division rule is only applicable for that circuit in which two resistances are in parallel with a current source. Current division rule can be used with a current source as well as voltage source.

SOURCE CONVERSION:-

Many times when we are solving a circuit or a problem it is quite difficult to solve it by using same source which is given in the problem. To make easy, we convert our given 
source. Means that, a current source can be changed by a voltage source and vice-verse. But have to fulfill it necessary condition. 

(1) Current source to voltage source:-

A current source can be converted into a voltage source if and only if a resistance is parallel to this current source. The circuit will be as,

Current source is converted into a voltage source in which a parallel resistance ‘R’ becomes in series with this voltage source. And the value of this voltage source is equals to,    V=I∙R  

Note:-The direction of voltage source is depends upon the direction of current source.

(2) Voltage source to  Current source:-

It is vice-verse of which we discussed above.

A voltage source can be converted into a current source if and only if a resistance is in series with this voltage source. The circuit will be as,