Ohm's Law

Whenever electric current flows through a conductor, the following three factors are present :

1. The pressure or potential difference V across the conductor (measured in volts) causing current to flow.
2. The opposition or resistance R of the conductor (measured in ohms) which must be overcome.
3. The current strength I (measured in amperes) which is maintained in the conductor as a result of pressure overcoming the resistance.

There exists a definite relationship between the three quantities involved and is known as Ohm's Law. It may be stated Thus :

"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 doesn't change"

In other words, V/I = Constant           or      V/I = R

where R is the resistance of the conductor between the two points considered.

OR

" According to ohms law, the flowing through a conductor is directly proportional to the potential difference, across the ends of the conductor and inversely proportional to the conductor resistance."

i.e.., I α V and I α 1/R

where, I is the current, V is the voltage and R is the resistance of the conductor material.

thus

I α V/R

OR

"At constant temperature the current flowing through a conductor is directly proportional to the potential difference between its ends."

I α V ;             V α I ;            V = IR ;

Where  R is a constant known as the resistance of the conductor.

OR

" The current is directly proportional to the voltage and inversely proportional to the resistance when the temperature remains constant."

i.e.., I = V/R