Formula for Finding Resistance
Below is a formula for finding
resistance often used in physics. We will also
discuss Ohm's Laws. Before we discuss the formula for finding
resistance, let's define what resistance is.
What is resistance in physics?
Resistance is defined by the resistance formula:
where:
Note that:

1 kilohm is 10 ^{3} ohms

1 megohm = 10 ^{6} ohms
What is Ohm's Law?
Ohm's Law for a metallic conductor is that
the current is proportional to the applied potential difference
for constant physical conditions. It follows that the
resistance of an ohmic conductor is constant and does not
change when the current changes.
The above equation for resistance (formula
for finding resistance) is not an expression of Ohm's Law but
the equation used to define resistance. The above formula for
finding resistance does not express the fact that V/I = R is
independent of I for an ohmic conductor.
