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

Rydberg formula, Rydberg formula (Rydberg): A formula which define all...

Rydberg formula (Rydberg): A formula which define all of the characteristics of hydrogen's spectrum, comprising the Lyman, Paschen, Balmer, Pfund series and Brackett,. For

Two positively charged particles at a separation, Questions: Regard as ...

Questions: Regard as two positively charged particles at a separation of 2.0 cm. One of the charged particles is shifting toward the other charged particle with a speed of 15 m

Angle between plane of polarization and plane of vibration, What is the ang...

What is the angle between plane of polarization and plane of vibration?

Explain briefly thermodynamic system , Normal 0 false false ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

What is speed of an electron and a proton in circular path, An electron and...

An electron and a proton are moving at the similar speed in circular paths in the similar uniform magnetic field.  The radius of the path of the proton is one of the following.

Help, hi, can you help me with sage homwork about physics

hi, can you help me with sage homwork about physics

Identify the action reaction pairs, Identify the action reaction pairs in t...

Identify the action reaction pairs in the following situations: a. Snowball hits a girl in the back.  Snowball pushes girl's back; girl's back pushes on snowball. b. A base

State any three uses of ir rays, Q. State any three uses of IR rays. (...

Q. State any three uses of IR rays. (a) Infrared lamps are utilized in physiotherapy. (b) Infrared photographs are utilized in weather forecasting. (c) As infrared radia

From which energy level did the atom fall, An electron in the hydrogen atom...

An electron in the hydrogen atom loses 3.02 eV as it falls to energy level E 2 . From which energy level did the atom fall?

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