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

Semiconductors, I want a clear explanation body full wave rectifier.

I want a clear explanation body full wave rectifier.

Force mc falling time mars, Surface gravity on Mars is roughly 1/3 that of ...

Surface gravity on Mars is roughly 1/3 that of the Earth. Consider you drop a rock initially at rest from a height Hm on Mars and it takes a time tg to hit the ground. From what he

Introduce concept about the carbon dioxide laser, Introduce concept about t...

Introduce concept about the carbon dioxide laser. A test target is vaporized and bursts within flame onto irradiation through a high power continuous wave carbon dioxide laser

State biot-savart law, State Biot-Savart's law. Using this law, derive the...

State Biot-Savart's law. Using this law, derive the expression for the magnetic field because of a current carrying circular loop of radius 'R', at a point which is at a distance '

Draw the energy band diagrams of a tunnel diode, Draw the energy band diagr...

Draw the energy band diagrams of a tunnel diode for different biasing conditions. Band  Diagrams  of  a  Tunnel  diode:   The  energy  band  diagram  for  a  heavily  doped unb

What are the components of endoscope, What are the components of endoscope?...

What are the components of endoscope? An endoscope can consist of following components • A rigid or flexible tube • A light delivery system to clarify the organ or object

What is the condition for resonance, What is the condition for resonance? ...

What is the condition for resonance? Condition for resonance: The condition of frequency of the oscillatory circuit is equal to frequency of the vibrating rod as: 1/(2 Π

Electric dipole, what should be the orientation of an electric dipole so th...

what should be the orientation of an electric dipole so that its potential enrgy is minimum

Ideal transformer, In an ideal transformer , the no. of turns in primary & ...

In an ideal transformer , the no. of turns in primary & secondary are 200 & 1000 respectively .If power input to primary is 10kW at 200V.Calculate i)output voltage ii)current in

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