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 balanced and unbalanced forces, Balanced and Unbalanced Forces:- ...

Balanced and Unbalanced Forces:- Newton's first law of motion states that "an object at rest stays at rest and an object in motion stays in motion with the similar speed and in

Draw the v-t graph of an automobile, Draw the v-t graph of an automobile th...

Draw the v-t graph of an automobile that accelerates uniformly from rest at t = 0.00 s and covers a distance of 180.0 m in 12.0 s.

Describe working of heat engine, Describe working of Heat engine Heat ...

Describe working of Heat engine Heat engine is a device by which a system is made to undergo a cyclic process that results in conversion of heat to work.  * It having of a

1, what is majority and minority charge carrier ?

what is majority and minority charge carrier ?

Moment of inertia, Calculate the moment of inertia of An 8.00-kg cylinder, ...

Calculate the moment of inertia of An 8.00-kg cylinder, of length 19.5cm and diameter 12.0 cm,about the central axis of the cylinder,if the cylinder is (1) thin-walled and hollow,

Understand how an endoscopy used in the invasive surgery, Understand how an...

Understand how an Endoscopy used in the invasive surgery. Endoscopy is a minimally invasive diagnostic medical process utilized to assess the interior surfaces of an organ thro

What is electrolytes, The liquids which permits the current to pass by them...

The liquids which permits the current to pass by them and also dissociates into ions on passing current by them are named electrolytes e.g. resolution of salts, bases and acids in

Earths rotation about its axis, The earth's rotation about its axis changes...

The earth's rotation about its axis changes measurably over time; You don't have to worry about the details; all you need to know is that our days are growing longer by about 2.3 m

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