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

What is the acceleration due to gravity on mars, Ngan has a weight of 314.5...

Ngan has a weight of 314.5 N on Mars and a weight of 833.0 N on Earth. a. What is Ngan's mass on Mars? b. What is the acceleration due to gravity on Mars, g Mars ?

What is the current in the circuit, In the circuit shown below, a potentiom...

In the circuit shown below, a potentiometer is used to vary the current to the lamp. If the only resistance is due to the lamp, what is the current in the circuit?

Special resistor materials: tungsten, Tungsten: Atomic numb...

Tungsten: Atomic number 74 Symbol W Atomic weight 183.85 Discovery Purified Tungste

Gravity.., what is quantum gravity

what is quantum gravity

Ray of light in air and flat piece of glass, A ray of light in air is occur...

A ray of light in air is occurrence upon a flat piece of glass. How acts the path that the light travels along when it is in the glass compare with the path in the air?

Schottky barrier diodes, The Schottky diodes are a semiconductor diode with...

The Schottky diodes are a semiconductor diode with a low forward voltage drop and a very fast switching action. The voltage drop at forward biases of around 1ma is in the range 0.1

Laser, what is the importance of laser?

what is the importance of laser?

Evaluate the deepest he could have been, In a movie, Tarzan evades his capt...

In a movie, Tarzan evades his captors by hiding underwater for many minutes while breathing through a long , thin reed . Assuming the maximum pressure difference his lungs can mana

Give the overview of newton formulation of physical laws, Give the overview...

Give the overview of Newton formulation of physical laws. Newton's formulation of physical laws was so influential which his equations are still in use nowadays. By the beginni

Magnetic effect, Determne the magnetic field due to a finit sraight wire of...

Determne the magnetic field due to a finit sraight wire of length 2l, carrying a steady current i. The point of interest P is l distance away from the middle point of wire O. So

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