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

Calculate maximum range r, A tank is filled up to a height 2H by a liquid a...

A tank is filled up to a height 2H by a liquid and is placed on a platform of height H from the ground .the distance x from the ground where a small hole is punched to get maximum

Pseudo force, pseudo force: A "force" that arises since an observer is...

pseudo force: A "force" that arises since an observer is naively treating an accelerating frame like an inertial one.

ULTRA SONICS, WHAT IS THE FREQUENCY OF ULTRA SONICS

WHAT IS THE FREQUENCY OF ULTRA SONICS

Diamond dosimetry, what is the working principle of diamond dosimeter and w...

what is the working principle of diamond dosimeter and whast are its advantages and disadvantages over other dosimeters?

Explain electrical bell, Electrical Bell: 1.An electromagnet, which is ...

Electrical Bell: 1.An electromagnet, which is made by winding insulated copper wire on a soft iron core. 2.An armature which is soft iron strip with spring. 3.A soft iron

The electric field strength is zero, a)  A positive point test charge q 0  ...

a)  A positive point test charge q 0  is placed at the midpoint p among the two equal positive charges q. What forces acts on it at or near this point p?   b)  Two charges 1X10 -

Nand gate, construction of nand gate?

construction of nand gate?

Electric charges, Two charges eachof q=+2 micro coloumb are placed at the v...

Two charges eachof q=+2 micro coloumb are placed at the vertices Q and R of the triangle .the sum of sides PQ and PR is 12cm and their product is 32 cm_2 .the potential at point P

The water will not spill, The water will not spill Get a small pail and...

The water will not spill Get a small pail and fill it nearly full with water . Swing it around rapidly at arms' length and the water will not spill because of centrifugal force

Plot the v-t graph showing the entire motion of the dragster, A dragster be...

A dragster begins from rest and accelerates for 4.0 s at a rate of 5.0 m/s2. It then travels at a constant speed for 2.5 s. A parachute opens, stopping the vehicle at a constant ra

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