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 about the term holography, Explain about the term holography. H...

Explain about the term holography. Holography Holography (through the Greek hòlòs entire + grafè writing, drawing) is a technique which permits the light scattered by an obj

Define principle ray II, Principle Ray II . Preliminary on the object side ...

Principle Ray II . Preliminary on the object side of the lens ray II heads toward the plane of the lens along a line that is parallel to the principle axis of the lens. At the plan

Magnus effect, Magnus effect: In a moving fluid a rotating cylinder dr...

Magnus effect: In a moving fluid a rotating cylinder drags some of the fluid around with it, in its direction of rotation. This enhances the speed in that region, and therefor

Properties of lines of flux, Properties of Lines of Flux To make the im...

Properties of Lines of Flux To make the imaginary lines of flux describe the behaviour of the magnetic field we must give them appropriate properties.  Thus lines of flux have

Evaluate voltage drop across the load resistance, Q. A transistor is connec...

Q. A transistor is connected in CE configuration. The voltage drop across the load resistance ( Rc) 3 k is 6 V. Find the base current. The current gain α of the transistor is 0.97.

Shm, if length changes then there is change in the time period how to sol...

if length changes then there is change in the time period how to solve these questions regards

Explain the acoustic cavitation, Explain the acoustic cavitation. Acous...

Explain the acoustic cavitation. Acoustic Cavitation: Usually, cavitation is the phenomenon where largely and small empty cavities are generated into fluids that expand to l

Bessal equation, Is there any physics expert willing to write me a 6 pages ...

Is there any physics expert willing to write me a 6 pages paper about Bassel equation (the physics of it) illustrating that with filter examples. I need ppt slides as well to help

What is the principle of millikans oil drop method, Q. What is the principl...

Q. What is the principle of Millikan's oil drop method? Principle This method is foundation on the study of the motion of uncharged oil drop under free fall due to grav

Illustrate the characteristics of a sound note, Illustrate the characterist...

Illustrate the characteristics of a sound note. What do you mean by Resonance? Illustrate with an example.

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