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

Describe the process of diffusion in cells, 1.  Describe the process of dif...

1.  Describe the process of diffusion in cells (not more than 2 pages).  2.  Derive the equation for Fick's second law. 3.  Draw a typical FRAP curve and explain its differen

Select the correct trajectory of the ball after it breaks, Q. Select the co...

Q. Select the correct trajectory of the ball after it breaks? A ball is being whirled on a string. At the instant shown in figure, the string breaks. choose the correct traject

What is meant by the sensitivity of a potentiometer, What is meant by the s...

What is meant by the sensitivity of a potentiometer? A battery E 1 of 4 V and a variable resistance R h are linked in series with the wire AB of the potentiometer. The length

Motion in one dimension, a ball is dropped from a bridge 122.5m high. afte...

a ball is dropped from a bridge 122.5m high. after the ball has been falling for2 sec another is thrown straight downwards after it. the initial velocity of the ball is such that

Mechanics, what is reduce mass in two mass system?

what is reduce mass in two mass system?

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

#NumerosCuanticos, si el numero atomico del sodio es 11 y su numero de masa...

si el numero atomico del sodio es 11 y su numero de masa es 22,diga¿cuantos electrones,protones y neutrones respectivamente,tiene su atomo neutro?

Determine the work produced by the steam turbine, A steam turbine takes in ...

A steam turbine takes in saturated steam at 300 C and outputs steam at 4 bar. If the efficiency of the turbine is 65%, calculate: a. The final composition (vapor vs. Liquid) of

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