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 musical sounds, Musical Sounds: Sound that produces pleasant ef...

Musical Sounds: Sound that produces pleasant effects on our ear is known as musical sound. Such as sound of flute, violin.

Heat energy, how heat energy is liberated during respiration?

how heat energy is liberated during respiration?

Dirac constant, Dirac constant; Planck constant, modified form; hbar A ...

Dirac constant; Planck constant, modified form; hbar A sometimes more convenient form of the Planck constant, explained as hbar = h/(2 pi).

Explain the kinetic theory, Explain the Kinetic Theory Kinetic theory l...

Explain the Kinetic Theory Kinetic theory looks at how each of these steps adds more internal kinetic energy (jiggle energy) to the material. A solid is a framework of atoms an

Explain change in kinetic energy, Two blocks are tied together by a horizon...

Two blocks are tied together by a horizontal string and pulled a distance of 2.7 m across an air hockey table with a constant force of 35 N. The force is directed at an upward angl

Factors on which resistance depends, Factors on which Resistance Depends: ...

Factors on which Resistance Depends: Resistance of the conductor depends on the following factors. Nature of the conductor. Length of the conductor. Area of cross sect

Define kepler''s laws, Johannes Kepler revealed three empirical laws by usi...

Johannes Kepler revealed three empirical laws by using the data on planetary motion, pertaining to the orbit of planets. These laws are contained here because of the huge importanc

Name the different methods of charging a battery, Different methods of char...

Different methods of charging a battery:  There are two general methods are employed for charging are:- A) constant current system and B) constant voltage system..

Define perfectly plastic body , An object which does not get its actual con...

An object which does not get its actual configuration at all on the removal of deforming force, though short the deforming force can be is a perfectly plastic body.

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