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

Cathode rays have, Cathode rays have: (1)Mass only (2)Charge only ...

Cathode rays have: (1)Mass only (2)Charge only (3)No mass and charge (4)Mass and charge both Ans:(4)Mass and charge both

Calculate the pressure and temperature, A box is divided into two parts of ...

A box is divided into two parts of equal volume via a partition. The box is thermally insulated from the surroundings. Consider that compartment 1 contains an ideal gas A at P 0 ,

What do you mean by dopplers shift, What do you mean by Doppler's shift? De...

What do you mean by Doppler's shift? Derive a mathematical expression for the apparent frequency heard by a moving listener when the source of sound is at rest. What is the effe

Tools for performance measurement in parallel algorithm, After the parallel...

After the parallel algorithm has been written as well as executed performance of both algorithms is one of other main concerns. In order to examine performance of algorithms there

Work and energy, A 0.15 kg glider is moving to the right on frictionless ho...

A 0.15 kg glider is moving to the right on frictionless horizontal air track with speed of 0.8 m\s. It has a head on collision with 0.3 kg glider that is moving to the left with a

Understand how an endoscopy used in the invasive surgery, Understand how an...

Understand how an Endoscopy used in the invasive surgery. Endoscopy is a minimally invasive diagnostic medical process utilized to assess the interior surfaces of an organ thro

Motion in one dimension, Motion of an object in a straight line is known on...

Motion of an object in a straight line is known one dimensional motion. The location of a particle in one dimensional motion can be defined by only one variable (say x). For a pa

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

State electric field lines in good metallic conductors, Electric field line...

Electric field lines In good metallic conductors: In good metallic conductors:  (i)   Static electric fields are not there (zero inside a conductor) (ii)  Charges reside

Illustrate working and construction of dud dells, Write short notes on the ...

Write short notes on the working of a thermopile. Illustrate working and construction of Dud dell's thermo galvanometer.

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