Question

What effect will it cause on the resistance of a conductor when
a) Length of the conductor is doubled?
b) Area of cross section is halved?
C) Temperature of the conductor is increased

Answer 1

Hey friend!

Here is your answer:

We know:

By ohm's law for ohmic conductors,

V = RI     ,where V = potential difference of the resistor, R = resistance, I = current flowing through the resistor.

Also,

R ∝ $\frac{length}{area of the cross section}$

For question 1) if length of the conductor is doubled,

As R ∝ length,

If length doubles, resistance will also double.

For question b) If area of cross section is halved,

R ∝ $\frac{1}{area}$

If area of cross section gets halved, resistance will double

For question c)  If the temperature of the conductor is increased,

the length and area of cross section of the conductor will fluctuate for expansion and the resistance changes variably . The change is different for resistors from conductors to super conductors.

I hope you understand and if you like my answer, please respond with a thanks.