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

Explain construction of michelsons interferometer, Q. Explain Construction ...

Q. Explain Construction of michelsons interferometer? It consists of two highly polished plane mirror M1 and M2, with two optically plane glass plate G 1 and G 2 which are of

Hookes law, Hookes Law Hooke's equation actually holds (to some extent)...

Hookes Law Hooke's equation actually holds (to some extent) in several other situations whereas an elastic body is deformed, like as wind blowing on a tall building, a musician

Chemistry in action - detergents, chemistry in action - Detergents A re...

chemistry in action - Detergents A result of high dissolving power, the logically happening water all time consists of dissolved matters, majorly ionic substances. Hard water h

Explain various types of equilibrium, Equilibrium can be spited in given ty...

Equilibrium can be spited in given types: (i) Stable equilibrium : After showing a charged particle from it's equilibrium point, if it goes back then it is called in stable equ

Simple pendulum frequency, A simple pendulum of frequency f has a metal bob...

A simple pendulum of frequency f has a metal bob.If the bob us negatively charged and is allowed to oscillate with a posively charged plate under it , the frequency will.? Ans) DUE

What is the mass of the planet newtonia, On the planet Newtonia, a simple p...

On the planet Newtonia, a simple pendulum having a bob with mass 1.25 kg and a length of 185.0 cm takes 1.42 seconds, when released from rest, to swing through an angle of 12.5 deg

Electromagnetism and electronics, the energy stored in the capacitor decrea...

the energy stored in the capacitor decreases with time as the capacitor discharges. After how many time constant is this stored energy one forth its initial value

Explain weightlessness, Explain Weightlessness When can you feel weight...

Explain Weightlessness When can you feel weightless? There are two basic ways. You can be far enough away from all large objects in the universe that the force of gravity due t

What are the stars, What are The Stars? The star is made of dust and ga...

What are The Stars? The star is made of dust and gas in space. Essentially it has many stages they are 1.black hole 2.nuetron star 3.supernova 4.red giant stage

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