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

Experiment on thermo electric thermometers, what are some advantages of th...

what are some advantages of the thermo-electric thermometer over the mercury in glass thermometer?

Which of the subsequent statements is true, Que: Consider a capacitor c...

Que: Consider a capacitor containing of two flat metal plates of one and the same size. The plates are opposite each other and they are well-aligned with each other. The plates

Electric field of an oscillating charge, Electric Field of an Oscillating C...

Electric Field of an Oscillating Charge An electric charge is executing simple harmonic motion, and the animation displays the electric field lines around it.

Describe escape velocity, Q. Escape Velocity An object will conquer the...

Q. Escape Velocity An object will conquer the force of gravity when its kinetic energy in the direction away from earth exceeds its potential energy. We find the smallest kinet

High value resistor, These resistors are usually of carbon composition, car...

These resistors are usually of carbon composition, carbon film on a ceramic rod and sealed in evacuated glass tube. End connections are made up of copper clad nickel-iron alloy.

Radioactive substance will be left after 5 half -life period, Q. What perce...

Q. What percentage of a given radioactive substance will be left after 5 half -life periods? The residual part of radioactive substance = ( ½ ) 5 Therefore the percentage

#PhysicsofVolleyball, Is there a way that you can gain potential energy and...

Is there a way that you can gain potential energy and release kentic energy in Volleyball?

How can we increase current sensitivity of a galvanometer, Q. How can we in...

Q. How can we increase the current sensitivity of a galvanometer? The current sensitivity of a galvanometer is able to be increased by (i) Rising the number of turns (ii

Heat, a lead bullet moves horizontally with a velocity of 130ms and embedde...

a lead bullet moves horizontally with a velocity of 130ms and embedded into a cement wall after collision. if the specific heat capacity of lead = 130J/KgC and all heat produces is

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