Question

How can I calculate resistance of a wire?

Answer 1

In this question we have to explain how we can find the resistance of a wire. So for this first we are going to understand what resistance is and when resistance was introduced and then we will understand how we can find the resistance of a wire.

Complete solution:
Resistance is a measure of opposition of current flow in an electrical circuit. It means that resistance is a property of material that opposes the flow of current. The unit of resistance is Ohm. Resistance was first introduced in Ohm’s law; which states that the voltages across a resistance are directly proportional to the current flowing in the wire when the physical conditions of the wire are the same.
$V \propto I$
Where,
V is the voltages across the wire in Volts and
I is the current flowing in the wire in ampere.
It implies following
$V = IR$
Where,
R is the resistance in the wire in ohms.
So, from the above formula we can see that if we have the values of I and V, we can find the resistance using this formula.
Result- Hence, from the above explanation we can see the way to find the resistance of a wire.

Note: Resistance of a wire is a very important property. We use this in various calculations. We can arrange resistors in two forms: series and parallel. We can find the total resistance using formula for series and parallel combinations respectively,
Series combination:
$R = {R_1} + {R_2} + ..........$
Parallel combination:
$\dfrac{1}{R} = \dfrac{1}{{{R_1}}} + \dfrac{1}{{{R_2}}} + .........$
Power of the circuit can also be found if we know the resistance of the circuit. Formula to find power is given below,
$P = \dfrac{{{V^2}}}{R}$
Where, P is the power of the circuit in Joule.