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

Electricity, Characteristics of resistances connected in parallel

Characteristics of resistances connected in parallel

Sound, experiments on how sound waves travel faster in iron

experiments on how sound waves travel faster in iron

Boolean algebra, (1) In Boolean algebra only two types of state variables (...

(1) In Boolean algebra only two types of state variables (0 and 1) are permitted. (2) The variables (A, B, C ....) of Boolean algebra are subjected to three operations.

Kinematics., a ball is thrown horizontally from a point 100 m above the gro...

a ball is thrown horizontally from a point 100 m above the ground with a speed of 20 m/sec .find the time it takes to reach the ground...

Electric current., design and draw circuit that implement master slave circ...

design and draw circuit that implement master slave circuits

Thermal detectors method of detection of ultrasonic waves, Explain the ther...

Explain the thermal detectors method of detection of ultrasonic waves. Thermal detectors method: It is the most generally used method of detection of ultrasonic waves. In th

Working of single –phase induction motor, Working of Single –phase inductio...

Working of Single –phase induction motor Working : Construction of a single -phase motor is same to that of a three -phase induction motor except that the stator is given wit

Millikan oil drop experiment, Millikan oil drop experiment (R.A. Millikan) ...

Millikan oil drop experiment (R.A. Millikan) A popular experiment designed to compute the electronic charge. Drops of oil were carried past a consistent electric field among c

Explain the reason when chemical changes, Chemical changes during: Dis...

Chemical changes during: Discharging: The current will flow from positive to negative plate in the external circuit. As current now enters by negative plate, the negative

How to identify a hard-boiled egg, How to identify a hard-boiled egg Se...

How to identify a hard-boiled egg Secure a fresh egg and a hard-boiled egg. Give every of them a spinning motion in a soup dish or a plate. View that the hard-boiled one spins

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