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

Electric potential, is the surface of a conductor is equipotential

is the surface of a conductor is equipotential

Determine about the rod in magnetic coil, Determine about the rod in magnet...

Determine about the rod in magnetic coil the rod is placed in a magnetic coil deliver alternating current, the rod suffers a change within length for each half cycle of alterna

Zero error of screw gauge, In a perfect instrument the zeros of the major s...

In a perfect instrument the zeros of the major scale and circular scale coincides with each other, in that situation screw gauge has zero-error, or else the measurement device is s

Poission;s theory, what is poission''s equation?Establish poisson''s equati...

what is poission''s equation?Establish poisson''s equation for space distribution of charges.discuss its significance.

Determine percentage of carbon in mild steel, The percentage of carbon in m...

The percentage of carbon in mild steel is (A) 0.08 to 0.3 %        (B) 0.5 to 1.4 % (C) 2.35 %                   (D) 0.5 % Ans: The percentage of carbon in mild st

Evaluate the uniform speed of gondola, Evaluate  the uniform speed of gond...

Evaluate  the uniform speed of gondola? Q. The world's largest ferris wheel with a radius of 50.0 m is located in Yokohama City, Japan. Each of the sixty gondolas on the wheel t

What are ultrasonic drilling and cutting, What are ultrasonic drilling and ...

What are ultrasonic drilling and cutting? Explain in short. Ultrasonic Drilling and Cutting Ultrasonic are utilized for making holes into very hard materials as like glass a

Determine the temperature and the entropy generation, Hexane is throttled f...

Hexane is throttled from 18.15 bar, 507.6 K to 0.1 bar.  Determine the temperature at the exit and the entropy generation. Steam is cooled under constant pressure from 400 o C,

Calculate the velocity of the ball, A boy is standing on an elevator which ...

A boy is standing on an elevator which is traveling downward with a constant velocity of 30 meters per second.  The boy throws a ball vertically upward with a velocity of 10 meters

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