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

Nickel cadmium batteries -construction, Nickel cadmium batteries -Construct...

Nickel cadmium batteries -Construction: The plates of a nickel cadmium battery are made by sintering a nickel plated steel screen with nickel carbonyl powder. The resultant pla

Electric field and the associated magnetic field, What the angles among the...

What the angles among the direction are of travel of light the electric field and the associated magnetic field? Answer: The magnetic field created by a changing electric

Calculate the magnitude of the axial force, The symmetrical scissors truss ...

The symmetrical scissors truss shown below is supported at point A and D. The support at D is a rocker bearing and does not produce a horizontal reaction.  A, B, C, D, E & F are pi

How to find out percentage error, Take the difference among your experiment...

Take the difference among your experimental value and your known value, and divide that difference by your know value. Say you experimentally found the force of gravity to be 8m/s

Band theory.., differentiate between direct and indirect band gaps

differentiate between direct and indirect band gaps

Give the applications of moseley''s law, Q. Give the applications of Mosele...

Q. Give the applications of Moseley's law. (i) The elements are organized in the periodic table according to the atomic numbers and not according to the atomic weights. (ii

Thin films, 2. Surface Crystallography and Epitaxy Fe thin films are grown...

2. Surface Crystallography and Epitaxy Fe thin films are grown on a single-crystal Al (100) substrate surface. The films grow with no dislocations (if they are thin enough) which

Determine the focal lengths of the lens, An object located four focal lengt...

An object located four focal lengths in front of a thin, converging lens is moved to within two focal lengths of the lens.  As a result, does the size of the image produced by

Compute the voltage gain with feedback, Q. The voltage increase of an ampli...

Q. The voltage increase of an amplifier without feedback is 100. If negative feedback is functioned with feedback fraction 0.1, compute the voltage gain with feedback. A F

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