In our previous post, we discussed about the resistance. Today we are about to study the Ohm's law.
Whenever electric current flows through a conductor , the following factors are present :
- The potential difference V across the conductor causing the current to flow.
- The opposition or resistance R of the conductor which must be overcome.
- The current I which in the conductor as a result of pressure overcoming the resistance.
The voltage difference across a conductor is directly proportional to the current which goes through it due to the voltage difference , provided the temperature of the conductor does not change.
The ratio of potential difference V between any two points of a conductor to the current I flowing between them is constant, provided the temperature of the conductor does not change.
V/I = constant
V/I = R
where R is the resistance of the conductor between the considered points.
This can be written as,
V = IR
This law is applicable to both DC and AC circuits. But it is complicated than DC .
Derived relations from Ohm's law
- Power is given by the product of voltage and current.W = VIUsing ohm's law we can rewrite this equation as,W = I2RW = V2/R