Question

Will current flow more easily through a thick wire or a thin wire of the same material, when connected to the same source? Why?

Answer 1

Hint:In order to solve this question, we need to first understand resistance.Resistance is the opposition produced by the wire whenever there is current passing through it. This is in accordance with Newton’s first law which states that the body opposes the cause of its change in state. We will use the general formula of resistance to check how it depends upon current and thickness of the wire.

Complete answer:
The general formula of resistance can be written as,
$R = \dfrac{{\rho l}}{A}$
Here, $R$ is resistance, $\rho $ is resistivity or proportionality constant, $l$ is length and $A$ is cross sectional area of wire.

So for two wires, we have the same resistivity and length but the area of two wires would be different. Since we know Area of thick wire would be greater than cross sectional area of thin wire as resistance is inversely proportional to the area, So Resistance of thick wire is less than resistance of thin wire and more the resistance of wire then less easily the current will flow.

Hence Current flow in thick wire is easy in comparison to thin wire because thick wire shows less resistance in comparison to thin wire.

Note:It should be remembered that more the current flow in wire the more the heat energy generated so for some specific cases wires need to have large resistance in order for controlled current flow otherwise it can damage the electrical equipment. Resistivity is the inherent property of the wire, it depends upon the material of which wire is made.