Question

Consider a wire that has resistance r, length l and the cross-sectional area

a. the correct expression for the resistivity of that wire is:

Answer 1

`\rho = (RA)/(L)`

Step-by-step explanation:

.As we know that the resistance of the wire is given as

`R = \rho (L)/(A)`

here we know that

A = cross-sectional area

L = length

R = resistance of wire

now multiply both sides of above equation with Area

`R A = \rho L`

now divide both sides with length of the wire

`\rho = (RA)/(L)`

so above is the expression of resistivity of wire in terms of resistance, Area and length of the wire

Answer 2

rho = R * A/l
rho is the resistivity in ohm meters.
R is the resistance in ohms
A is the cross sectional area in meter^2
l is in meters.