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 free fall acceleration, What is free fall acceleration? On eart...

What is free fall acceleration? On earth free fall acceleration is 9.81 meters per second per second or 32.2 feet per second per second, not containing air resistance. Aroun

Explain ohm''s law, OHM's Law: The current passing by a conductor is di...

OHM's Law: The current passing by a conductor is directly proportional to the potential difference applied across it's end given, the temperature and other physical conditions

Define wavelength, (i) It is the length of single wave. (ii) Wavelength ...

(i) It is the length of single wave. (ii) Wavelength is similar to the distance covered by the wave during the time in which any one particle of the medium done one vibration ab

One would expect proton to have very large, One would expect proton to have...

One would expect proton to have very large: (1) Ionization potential (2) Radius (3) Charge (4) Hydration energy Ans:(4) Hydration energy

Magnetic susceptibility, If the material is in the crystalline form, how wi...

If the material is in the crystalline form, how will the susceptibility be affected?

Isochoric process of thermodynamic, A thermodynamic process, in which the v...

A thermodynamic process, in which the volume of gas always same is known as isochoric process. In this process, the work completed by the body is zero. Therefore from first law

Calculate the entropy change - ideal gas, 1. Calculate the entropy change w...

1. Calculate the entropy change when 1 kmol of an ideal gas at 300 K and 10 bar expands to a pressure of 1 bar if the temperature stays constant. 2. What is the change in entrop

Cathode rays are, Cathode rays are : (1)Protons (2)Electrons      ...

Cathode rays are : (1)Protons (2)Electrons      (3)Neutrons (4)alfa -particles Ans; (2)Electrons

How energy is delivered to such a bulb in an hour, The power distribute to ...

The power distribute to a 15 watt light bulb in normal operation is 15 watts. In normal operation how greatly energy is delivered to such a bulb in an hour? Feedback:

Illustrates the evidence to support the big bang theory, Q. Illustrates the...

Q. Illustrates the evidence is there supporting the Big Bang theory? Answer:- In brief the universe is expanding. Each of the galaxies we have observed that are utmost awa

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