Question

a)If the length of AB is changed into 40cm,What will be the resistance?

Answer 1

Resistance = ρl/A

Where, ρ = resistivity of wire

l = Length of wite

A = Area of cross section of wire

So, If we change Length by 4 times then Length will be 4 times and resistivity and Area of cross section will not be affected.

So, New resistance = ρ(4l)/A

New resistance = 4 × ( ρl/A)

New resistance = 4 × Resitance

New resistance = 4 × 6

New resistance = 24 ohm

Therefore, Resitance will be 24 ohm when Length is changed to 40cm.

Hope it helps.......✌