Question

Give two points of difference between resistance and resistivity.

Answer 1

Hint: Resistance is defined as the measure of the degree to which a conductor impedes the flow of electric current induced by a voltage. Resistivity of a material is defined as the resistance offered by a unit length and cross-sectional area by a wire of the material of the conductor. Inverse of resistance is conductance whereas the inverse of resistivity is conductivity.

Complete solution:

Resistance	Resistivity
Resistance can be defined as the property of the material which creates an obstruction in flow of current.	Resistivity can be defined as the physical property of a material which is having a particular dimension.
The symbol of resistance is R.	The symbol of resistivity is $\rho$.
Resistance is directly proportional to length and temperature of the material and inversely proportional to the cross-sectional area of the material.	Resistivity is proportional to the nature and temperature of the material and does not depend on the length and area of the material.
S.I. unit of resistance is Ohms i.e. $\Omega$.	S.I. unit of resistivity is Ohm-meter i.e. $\Omega m$.
Resistance is an extrinsic property of the material.	Resistivity is an intrinsic property of the material.
The property of resistance is used in heaters, sensors, etc.	Resistivity is used for quality control test o calcareous soil.

Note:
In case of conductors, resistivity rises with the increasing temperature while it decreases with the increasing temperature in insulators. As the temperature of the material rises, the number of phonons increases because of which the electrons and photons collide. Thus, when the temperature goes up, the resistance increases. Resistivity is also known as specific resistance. Resistivity of a copper ball and copper wire will be the same but the resistance of a copper ball and a wire will be different.