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

Advantages and disadvantages of three phase system, Advantages and disadvan...

Advantages and disadvantages of three phase system over single phase System A) In a single phase circuit the power delivered is pulsating. In three phase system the total power

Determine grating element in specturm, A beam of light of wavelength λ = ...

A beam of light of wavelength λ = 5000Å falling normally on a plane diffraction grating. The 1 st order spectrum is derived in a direction making an angle θ 1 with the norma

Explain electroplating, It is a method of depositing a thin layer of one me...

It is a method of depositing a thin layer of one metal over one more metal by the method of electrolysis. The articles of cheap solids are coated with valuable metals like silver a

Internal energy, When do you use Wn instead of work - A?

When do you use Wn instead of work - A?

Energy transformation on a roller coaster, Energy Transformation on a Rolle...

Energy Transformation on a Roller Coaster A roller coaster ride is a thrilling experience that includes a wealth of physics. Part of the physics of a roller coaster is the phys

Force, Force: Force may be defined as a push or a pull upon an object. ...

Force: Force may be defined as a push or a pull upon an object.  In the English system the pound (1b) is used to express the value of a force.  For example, we say that a force

What do you mean by length contraction, Q. What do you mean by Length Contr...

Q. What do you mean by Length Contraction? The length of any object in a moving frame will appear for shortened in the direction of motion. The amount of contraction can be cal

Explain constructive interference, It appears the intensity will be maximiz...

It appears the intensity will be maximized at that positions where path dissimilarity is an integral multiple of wavelength  these points are called as points of constructive inter

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