Resistivity, Physics

Assignment Help:

RESISTIVITY:

Resistance may be defined as that property of a substance which opposes (or restricts) the flow of current (or electrons) through it. The practical as well as MKS (or SI) unit of ohm (O). 1 ohm is defined as that resistance between two points of a conductor which produces a current of one ampere. When a potential difference of 1 volt is applied to it.

If I is the current flowing through a conductor of resistance R across which a potential difference V is applied then according to ohm's law.

                                                                                      I=V/R

Where V is in volts, R is in the ohms and I is in amperes.

Resistance of a material is:

(a)          Directly proportional to its length, l R α l

(b)         Inversely proportional to its area of cross section a, Rα1/a

Combining above two facts me have R α l/a

   Or       R=ρl/A

Where ρ(rho) is a constant depending upon the nature of the material and is known as the specific resistance or resistivity of the material. Putting l=1 and a=1 expression we have R=ρ. Hence resistance of a material of unit length having unit cross-sectional area is defined as the resistivity.


Related Discussions:- Resistivity

What is the difference between unit cell and primitive cell, What is the di...

What is the difference between unit cell and primitive cell In primitive cell, number of atoms per unit cell is one while if number of atoms per unit cell is greater than one i

Explain magnetic bearing, Explain magnetic bearing The horizontal angle...

Explain magnetic bearing The horizontal angle among the line and magnetic meridian passing through one of the extremities of the line is known as magnetic bearing.

Displacement and velocity, an object moves from postion +16m to the postion...

an object moves from postion +16m to the postion +47m in 12s.what is its total displacement and its average velocity?

Explain about the V-i characteristics of constant voltage, Draw and explain...

Draw and explain V-I characteristics of constant voltage and constant current sources. Ans: V-I Characteristics of Constant Voltage Source: A voltage source that has very low

Spaces Trip, We all know that some astronaut had landed in the moon to chec...

We all know that some astronaut had landed in the moon to check out how''s going on the moon. But why only a few astronaut? People created the Apollo and they made it. They sent so

Meissner effect, Meissner effect (W. Meissner; 1933): The reduction of...

Meissner effect (W. Meissner; 1933): The reduction of the magnetic flux in a superconducting metal while it is cooled below the transition temperature. i.e., superconducting m

Degree of freedom of monoatomic gas, If instead of molecule, we assume a mo...

If instead of molecule, we assume a molecular of a monatomic gas, which having of a one atom, the translational motion can take place in any direction in space. Thus it can be solv

Coulombs law, anyone guide me about the explanation of coulombs law

anyone guide me about the explanation of coulombs law

Define band emission spectrum, (i) It having of district bright bands. (...

(i) It having of district bright bands. (ii)It is given by an excited source in molecular state. (iii) E.g. Spectra of molecular NH 3 , CO, H 2 etc.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd