Difference between Resistance and Resistivity

The resistance and resistivity concept is one of the most fundamental as well as an essential part of the concept of current & electricity. The major difference between resistance and resistivity of the material is that the resistance resists the electron flow while the resistivity is the material’s property which describes the resistance of the material with an exact measurement. The differences between these two are explained in detail below. This comparison will aid engineering students to acquire a complete overview of the topics.

Difference between Resistance and Resistivity

The difference between resistance and resistivity includes what is resistance, resistivity, and their key differences.

What is Resistance?

The resistance can be defined as the material’s property which makes an obstruction within the current flow. As the voltage supply is given across the conductor, then the electrons flow will be there within an exact direction. So the heat can be generated while electrons flow collapses with molecules or atoms. These will oppose the flow of electrons within a material. This is named as the resistance and it is denoted with the following formula.

R = ρ x l / a

Where,

‘l’ is the conductor’s length

‘a’ is the conductor’s cross-section area

‘ρ’ is the resistivity of the material.

‘R’ is the resistance

resistance
resistance

Factors Affecting Resistance

The wire resistance mainly depends on the following factors.

  • When the length of the wire increases then automatically resistance of the wire will be increased
  • The conductor’s cross-section area is inversely proportional to the resistance.
  • It depends on the object of the wire.
  • The resistance of the object mainly relies on its temperature.

What is Resistivity?

The precise resistance is known as resistivity. It signifies the resistance of the object which has precise dimensions like the material which has one-meter length as well as one square meter region of a cross-section.

resistivity
resistivity

The material’s resistivity formula is given below.

ρ = R x a / l

Where

’l’ is the conductor’s length

‘a’ is the conductor’s side view area

‘R’ is the material’s resistance

Here ohm meter is the SI unit for the resistivity and it is directly proportional to the material’s temperature.

Comparison Chart of Resistance and Resistivity

The comparison chart of the resistance and resistivity mainly include the following.

Distinguishing Property

Resistance

Resistivity

Definition

It is the physical property of a material which opposes the electron flow

It is the physical property of a particular material which have specific dimensions

Proportionality

It is directly proportional to the temperature & the length whereas it is inversely proportional to the cross-sectional region of the substance.

Resistivity is mainly proportional to the temperature & the nature of an exact material.

Symbol

The symbol of the resistance is R

The symbol of the resistivity is ρ

Formula

R = V/I or,

R = ρ(L/A)

ρ = (R×A)/L

 

SI Units

 

The SI unit is Ohms

The SI unit is Ohms-meter

Applications

It is used in various places such as fuses, heaters, sensors, etc.

 

It can be used as a quality control test used in calcareous soil.

Dependence

It depends on temperature, length, and side view region of the conductor

It depends only on temperature

Thus, the main differences between resistance and resistivity are discussed in the above table which is essential to understand. These comparisons will help you in most exams of engineering students. Here is a question for you, what is the SI unit of resistivity?

 

 

 



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