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

Find the current in the coil - electric current, A magnetizing force of 800...

A magnetizing force of 8000A/m is applied to a circular magnetic circuit of mean diameter 30cm by passing a current by a coil wound on the circuit. If the coil is uniformly wo

How height and pressure affect the boiling point of water, Q. How does the ...

Q. How does the height and air pressure affect the boiling point of water? Answer:- The only factor that finding the boiling point of water at any altitude is the barometr

Internal combustion engine, Truck has a 100 kW engine power and 40 % effici...

Truck has a 100 kW engine power and 40 % efficiency . As oil burn in an hour if q = 4.4 to force multiplication 10 to 7 ?

4, #question.5.

#question.5.

Projectile motion - distance from the launch point, A projectile is launche...

A projectile is launched from zero height with an initial angle, θ, above the horizontal and with an initial velocity, vi. a. Show that the range of the projectile the distance

Explain magnetic dipole moment., Consider a current loop where the circulat...

Consider a current loop where the circulating current is I. This may be for an example of a coil carrying a current. We will assume that the current loop lies within a single plane

WORK AND ENERGY, A boy throws a ball of mass 20 kg vertically upwards.It ra...

A boy throws a ball of mass 20 kg vertically upwards.It raises to a maximum height of 100 m.At what height will the kinetic energy be reduced to 70%?

Resisitivity, properties of low and high resistive materials

properties of low and high resistive materials

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