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 refractive index of glass, A glass sphere of radius 15 cm has...

A glass sphere of radius 15 cm has a small air bubble at a distance of 6 cm from its centre. When viewed normally along its diameter from the nearest side, the bubble seems to be 7

Guglielmo marconis experiments on wireless transmission, Q. Which of the fo...

Q. Which of the following isn't true of Guglielmo Marconis experiments on wireless transmission Answer:- A) In 1901 he broadcasted a signal from Newfoundland to England

Atomic structure, Atoms are particles of elements, substances that could no...

Atoms are particles of elements, substances that could not break down further. In examining atomic structure through, we have to clarify this statement. An atom cannot be broken do

Moving the bar magnet rapidly away from the loop, Question: A wire loop...

Question: A wire loop smears in a horizontal plane. Alongside the loop is a vertical bar magnet south end up. The bar magnet is divide by the plane of the loop. A person is shi

What is electromagnetic induction, Q What is electromagnetic induction? ...

Q What is electromagnetic induction? The phenomenon of producing an induced emf because of the changes in the magnetic flux associated with a closed circuit is known as electr

Axis perpendicular to the rod, A non uniform rod AB has a mass M and length...

A non uniform rod AB has a mass M and length 2L the mas per unit length of the rod is mx at a point of the rod distant x from A.find the moment of inertia of this rod about an axis

Balanced forces - problems with sitting still, Example 1 - A bird feeder in...

Example 1 - A bird feeder in your yard has a total mass of 3.0 kilograms and is supported as shown. What is the force on the top wire? The bird feeder is not falling so the forc

Find the electric flux, The elctric field in a certain region of space has ...

The elctric field in a certain region of space has components E x = 6.0 N/C, E y = 7.0 N/C, and E z = 0. Find the electric flux though the surface x = 6 y , 0 x

What is the wavelength of that sound wave, When an orchestra is tuning up, ...

When an orchestra is tuning up, the first violinist plays a note at 256 Hz. a. What is the wavelength of that sound wave if the speed of sound in the concert hall is 340 m/s?

Flux of the electric field , a) A charge Q is placed at the centre of a cub...

a) A charge Q is placed at the centre of a cube. determine the flux of the electric field through the six surfaces of the cube. b)  Determine the magnitude of the electric field

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