Question

two wires A and B of equal mass and same mass are taken.the diameter of wire a is half the diameter of wire B.if resistivity of wire A is 24ohm calculate resistence of wire B

Answer 1

Hi...

R = resistivity× length of the wire/ ara of cross section of wire

Since, both the wires are made of same metal, their resistivity will be same.

Resistance of wire A, RA = 24 OHM =pL/A

p = resistivity
L = length of wire
A = area of cross section of wire
= πd²/4
RA = 4pL/πd²

half the diameter of the wire B is equal of that of A.
D/2 = d
D = 2d

So RB = 4pL/πD² = 4pL/4πd² = (1/4)(4pL/πd²)
RB = RA/4 = 24/4 = 6 OHM....


Hope this helps u!