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

Astronomy, The birghtness of objects past Neptune actually varies approxima...

The birghtness of objects past Neptune actually varies approximately as 1/d^4. Why is that the case?

What is nuclear radiations, According to Rutherford's experiment when a sa...

According to Rutherford's experiment when a sample of radioactive substance is place in a lead box and permit the emission of radiation by a small hole only. When the radiation ent

Determine the Effect of air resistance, An object in free fall has an accel...

An object in free fall has an acceleration of 9.80 m/s 2 assuming that there is no air resistance. What is the speed of an object dropped from the top of a tall cliff 3.50 s a

Obt, Obtain expression for an optical path difference for formation of circ...

Obtain expression for an optical path difference for formation of circular fringe in Michelson''s interferometer

Motion WS, a rocket is launched upward from a building that is 29m above th...

a rocket is launched upward from a building that is 29m above the ground. the rocket was launched (upward) at 18m/s, what was the time to reach the ground below the building?

Define angular momentum, The turning movement of a particle about the axis ...

The turning movement of a particle about the axis of rotation is called the angular momentum of the particle and is measured as the product of the linear momentum and the perpendic

Oscillations, M is the magnetic moment of bar magnet and T is time period ...

M is the magnetic moment of bar magnet and T is time period of oscillation. If we make M as M/4 then what will be the time period

Electric field, Can we take a negative test charge to find electric field?

Can we take a negative test charge to find electric field?

Negative feedback principle, Negative feedback principle: The idea tha...

Negative feedback principle: The idea that in a system where there are self-propagating conditions, those new conditions tend to act against earlier existing circumstances. Su

What is hystersis, The lagging of an effect behind its cause; especially th...

The lagging of an effect behind its cause; especially the phenomenon in which the magnetic induction of a ferromagnetic material lags behind the changing magnetic field.

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