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 concept of galaxy travelling toward earth, An astronomer observes...

An astronomer observes that a molecule in a galaxy travelling toward Earth emits light with a wavelength of 514 nm. The astronomer identifies the molecule as one that actually

Calculate the potential differences across each resistor, Q. In the given c...

Q. In the given circuit, calculate the potential differences across each resistor Solution : i) R s = R 1 + R 2 + R 3 = 10Ω ii) Current in circuit I = V/R s

Determine the forbidden gap of germanium, For germanium the forbidden gap i...

For germanium the forbidden gap is (A) 0.15ev. (B) 0.25ev. (C) 0.5ev. (D) 0.7ev. Ans: For germanium the forbidden gap is 0.7ev.

Why material in solid state are crystalline, Why material in solid state ar...

Why material in solid state are crystalline Most of the materials in solid state are crystalline. Between these many are in the polycrystalline state. To get single crystal one

Explain simple harmonic motion, Explain Simple Harmonic Motion Many rep...

Explain Simple Harmonic Motion Many repeating motion problems can be solved by taking the displacement as   where d is distance in meters, A is amplitude in meters,

What is solenoid? , A solenoid is a coil wound into a tightly packed helix...

A solenoid is a coil wound into a tightly packed helix. In physics, the term solenoid shows  a long, thin loop of wire, often wrapped over a metallic core, which makes a magnetic f

Current and time? help!, If the current in a wire of a CD player is 14.0 mA...

If the current in a wire of a CD player is 14.0 mA, how long would it take for 1.90 C of charge to pass a point in this wire? Answer in units of s

Ray optics, a tiny air bubble inside a glass slab appears to be 6 cm deep w...

a tiny air bubble inside a glass slab appears to be 6 cm deep when viewed from one side and 4 cm deep when viewed from other side. find the thickness of slab

Michelson interferometer, how Michelson interferometer can be used to measu...

how Michelson interferometer can be used to measure the wavelength of sodium light.

Define perfectly plastic body , An object which does not get its actual con...

An object which does not get its actual configuration at all on the removal of deforming force, though short the deforming force can be is a perfectly plastic body.

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