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

Determine the natural convection heat transfer coefficient, 1) A pot such m...

1) A pot such made by Revere Copper ("Revereware") has two different metals composing the bottom of the pan- a stainless steel pan "body" with a copper base formed to the pan on th

What is the universal law of universal gravitation, What is the universal l...

What is the universal law of universal gravitation? Statement that any particle of matter in the universe attracts any other with a force varying directly as the product of the

Define uniform velocity, (UNIFORM VELOCITY) (i) When instantaneous velo...

(UNIFORM VELOCITY) (i) When instantaneous velocity and average velocity of a body are equivalent, then the body moves with uniform velocity. (ii When instantaneous velocity

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??

Calculate the maximum kinetic energy of photoelectrons?, Light described at...

Light described at a place by the equation E=100[sin(5*10^15)t + sin(8*10^15)t] falls on the metal surface having work function 2eV.calculate the maximum kinetic energy of photoel

Sievert, Sievert; Sv: The derived SI unit of dose equivalent, explaine...

Sievert; Sv: The derived SI unit of dose equivalent, explained as the absorbed dose of ionizing radiation multiplied through internationally-agreed-upon dimensionless weights,

Connecting rod, key dimensional features in connecting rod?

key dimensional features in connecting rod?

Where do I upload, Where do I upload questions and answers for students?

Where do I upload questions and answers for students?

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