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

Materiel heat Sinking, Respected Sir, I am only knowing about materia...

Respected Sir, I am only knowing about material name that can be sink heat much longer area, it can be possible or not? if it possible, how to its work to sink.? Please..

Electrostatics , Y the charge n voltage. Remain constant ven we connect cap...

Y the charge n voltage. Remain constant ven we connect capacitors in series. N parallel. Respectively??

Lenses, Older people wear eye glasses with bifocal corrective lenses . What...

Older people wear eye glasses with bifocal corrective lenses . What is the eye defect that necessitate this eye glasses ?

Coulombs law of two charged particles, Q. As-per to Coulombs Law if two ch...

Q. As-per to Coulombs Law if two charged particles are repelled with a given force at a distance d by what multiple will the force decrease by if d is increased by 4 times? An

Galilean relativity, Galilean Relativity Galilean invariance or Galilea...

Galilean Relativity Galilean invariance or Galilean associatively states which the laws of motion are the similar within all inertial frames. Galileo Galilei first define this

Ray optics, how do i start studying for this topic where should i start

how do i start studying for this topic where should i start

Action and reaction with a roller skate, Action and reaction with a roller ...

Action and reaction with a roller skate Place a roller skate on a smooth floor. Step on the roller skate with one foot and take a step forward with the other. Observe that the

Describe mosley''s law, Mosley studied the characteristic X-ray spectrum of...

Mosley studied the characteristic X-ray spectrum of a number of a heavy elements and concluded that the spectra of dissimilar elements are very same and with enhancing atomic value

The red, A board with a number of  green, blue and  red coloured  switches ...

A board with a number of  green, blue and  red coloured  switches  is normally seen  near  the entrance of each house . What is the purpose of this board? What is the difference  a

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