Question

Mention the expression for the resistance in terms of resistivity and explain the symbols

Answer 1

Explanation:

a) Resistivity is a fundamental property of a material that quantifies how strongly it resists electric current.

\rho =R{\frac {A}{\ell }}ρ=R

ℓ

A

is the expression for the resistivity of a substance where R is the electrical resistance of a uniform specimen of the material, \ellℓ is the length of the specimen, A is the cross-sectional area of the specimen and ρ is the resistivity of the substance.

(b) The SI unit of resistivity is ohm-meter (Ω⋅m)

(c) Resistance varies due to change in size or shape of the substance but resistivity is same for every substance of same material.

(d) Resistivity depends on nature of material and Temperature but doesn't depend on shape and size of the substance.