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

Heat, what is thermal conductivity ?

what is thermal conductivity ?

#title, Ask questiA 1.10×10-2-kg bullet strikes a 0.300-kg block attached t...

Ask questiA 1.10×10-2-kg bullet strikes a 0.300-kg block attached to a fixed horizontal spring whose spring constant is 2100 N/m and sets it into oscillation with an amplitude of 1

Explain electric circuit, Electric Circuit: The path by which an electr...

Electric Circuit: The path by which an electric current passed is known as an electric circuit. The electric appliances are known as resistance.

Young''s double slit experiment (ydse), Monochromatic light (single wavelen...

Monochromatic light (single wavelength) falls on two narrow slits S1 and S2 which are very close together acts as two coherent sources, when waves coming from two coherent sources

Dielectric, what is electronic polarization?

what is electronic polarization?

Explain the thermodynamics - heat and work, Explain the Thermodynamics - He...

Explain the Thermodynamics - Heat and Work Thermodynamics is an area of science which looks at how changes in energy, work and the flow of heat influence each other. It can exp

Kilogram, kilogram; kg: The basic SI unit of mass, that only SI unit w...

kilogram; kg: The basic SI unit of mass, that only SI unit which still maintained by a physical artifact: a platinum-iridium bar kept in the International Bureau of Weights an

Component simple harmonic motions, When the component simple harmonic motio...

When the component simple harmonic motions have dissimilar periodic times: The resultant curve may be attained in this case by dividing the circumferences of the two circles of

How far does the boat coast, A power boat of mass 500 kg is cruising at a c...

A power boat of mass 500 kg is cruising at a constant speed of 8.9 m/s. The propeller provides a drive force of 765 N. The driver of the boat shuts off the engine, and the boat coa

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