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

What is the cause of brownian motion, What is the cause of Brownian motion?...

What is the cause of Brownian motion? Molecules in a gas move constantly, freely, randomly, in all directions and at high speeds. They are able to do so because the intermolecu

Fourth harmonic-standing waves on a string, Fourth Harmonic-Standing Waves ...

Fourth Harmonic-Standing Waves on a String There are a variety of patterns that could be generates through vibrations inside a string, slinky, or rope. Every pattern correspond

Unit and Dimensions, Physics is one of the types of science. Science works ...

Physics is one of the types of science. Science works according to scientific method . The scientific method accepts only logic, reason, and experimental evidence to tell betw

Formation of stationary waves in stretched strings, Illustrate the formatio...

Illustrate the formation of stationary waves in stretched strings and thus deduce the laws of transverse waves in stretched string.

How we calculate the speed of the water of a river, A boat can travel at a ...

A boat can travel at a speed of 3 m s -1 on still water. A boatman needs to cross a river whilst covering the shortest possible distance. In what direction should he row with resp

Why in inelastic collisions angle of momentum is conserved?, Mass of the sy...

Mass of the system is same. since, p=mv momentum remains same

The earth’s magnetic field, The earth’s magnetic field: The earth acts ...

The earth’s magnetic field: The earth acts as a magnet and the lines of force produced by it follow the pattern shown in the diagram below. If the Earth were completely symm

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