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

How many days would there be in an earth year, If a meteorite hit the Earth...

If a meteorite hit the Earth and moved it 2.41x 10 10 m closer to Venus, How many days would there be in an Earth year?

Determine the critical angle and refractive index, A luminous point object ...

A luminous point object is placed at a depth of 0.5m inside a liquid. A circular patch of light of radius 0.05675 m is prepared on the surface. Determine the critical angle and re

What is block hole?, A blackhole is a region of spacetime from which gravit...

A blackhole is a region of spacetime from which gravity prevents anything, including light, from escaping. The theory of general relativity predicts that a sufficiently compact mas

Illustrate the chemical vapour deposition method in brief, Illustrate the c...

Illustrate the chemical vapour deposition method in brief. Chemical vapour deposition method (CVD): A number of vapour phase deposition process have been developed for produ

How temperature of sun rays increase by sunlight reflected, Does sunlight r...

Does sunlight reflected off a mirror enhance the temperature of the sun-rays? A standard planar mirror will not enhance the energy contained in the rays that reflect off it. In

Write the relation among mobility and drift velocity, Write the mathematica...

Write the mathematical relation among mobility and drift velocity of charge carriers in a conductor. Name the mobile charge carriers responsible for conduction of electric curre

Explain single crystal growth, Single crystal growth. The single crysta...

Single crystal growth. The single crystals are grown either by the Czochralski (CZ) method or by the Float Zone (FZ) method. It having of a furnace with a gradient in temperatu

Magnetism, can i get assistance here with questions involving the design of...

can i get assistance here with questions involving the design of a permanent magnet magnetic bearing?

Determine work output unit mass of air & thermal efficiency, Consider air (...

Consider air (ideal gas) as working substance inside a piston-cylinder device (closed system). This air undergoes a power cycle as shown in figure. Determine work output per unit m

Deriving a working equation, Hi, i am max a physics student working on a pr...

Hi, i am max a physics student working on a project. Can you help me derive a working equation from faradays equation and ampere equation in rectangular coordinates? I am trying to

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