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

Determine the volume of the bubble, As shown in the figure below, a bubble ...

As shown in the figure below, a bubble of gas with a volume of 1.20 cm3 is released under water. As it rises to the surface, the temperature of the bubble enhances from 27°C to

What wavelength is formed by this pipe, An organ pipe which is open at both...

An organ pipe which is open at both ends resonates at its fundamental frequency.  Neglecting any end effects, what wavelength is formed by this pipe in this mode of vibration i

Help, http://s17.postimage.org/8pyqqqbm7/Untitled000.png

http://s17.postimage.org/8pyqqqbm7/Untitled000.png

Refraction - ripple tank , In a ripple tank two regions A and B can be crea...

In a ripple tank two regions A and B can be created by introducing a pile of glass plates in region B. Thus region B is a shallow water region while region A is a deep water re

Physics calculus-based, your dog is running around the grass in your backya...

your dog is running around the grass in your backyard.he undergoes successive displacement 3.50 m. on south,8.20 m northeast, and 15.0 m west.what is the resultant displacement?

Young double slits experiment, sketch the setup abd show the angulare dista...

sketch the setup abd show the angulare distace between successive dark bands is----------

Magnetic flux heat energy, time dependent magnetic flux that is changing fr...

time dependent magnetic flux that is changing from t=0 to t=torque varies as the flux is passing through stationary coil that has electrical resistance R. Find the amount of heat e

Physics, Current time base generator

Current time base generator

High frequency alternating current by a loud speaker, Give reason that ultr...

Give reason that ultrasonics not be produced by passing high frequency alternating current by a loud speaker At these high frequencies, inductive reactance is so high where is

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