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

Thermometer, Construction of a thermometer

Construction of a thermometer

Deflection magneto meter, why deflection magnetometer can not be worked at ...

why deflection magnetometer can not be worked at poles?

Are heat fuses necessary, Are heat fuses necessary? The working temper...

Are heat fuses necessary? The working temperature range of the fiber optics ordinary end is critical if the performance of the system is to be kept and the life guaranteed. A

Why are polarized sunglasses are effective, Question Why are polarize...

Question Why are polarized sunglasses are effective? Answer: If it weren't for the fact that surfaces that produce glare have a tendency to absorb vertically polariz

Moments, calculating the distance in effective handle.

calculating the distance in effective handle.

Moment of inertia problem, Does the moment of inertia of a cylinder change ...

Does the moment of inertia of a cylinder change if the direction of the rotation axis is changed, but it still goes through the center of mass?

Units and measurement.., the unit of force and length are doubled, the unit...

the unit of force and length are doubled, the unit of energy will be

Kinematics of projectile motion, Kinematics of Projectile Motion One of...

Kinematics of Projectile Motion One of the powers of physics is its capability to use physics principles to form predictions about the final outcome of a moving object. Such pr

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