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

Electrical energy, Electrical energy: Electrical energy is the ability ...

Electrical energy: Electrical energy is the ability of an electrical system to do work. Energy is expended when work is done and the amount of energy used is equal to the wo

What is electric flux, What is electric flux? Write its S.I. units. Usin...

What is electric flux? Write its S.I. units. Using Gauss's theorem, assume an expression for the electric field at a point because of a uniformly charged infinite plane sheet.

What are the affect does electricity have on the soil, Q. What are the affe...

Q. What are the affect does electricity have on the soil? Answer:- Electrical current and ions are able to cause certain molecules (and moisture) to adhere to soil. Large

Describe what is one beat , If the intensity of sound is maximum at time t ...

If the intensity of sound is maximum at time t = 0, one beat is known as formed when intensity changes into maximum again after becoming minimum once in among.

Explain the working of transformers, Explain the working of Transformers ...

Explain the working of Transformers A transformer often uses a core, which looks like a square donut of iron, to change the voltage applied to the primary coil to a new larger

What is the use of surface tension? , It is jut a field of physics which is...

It is jut a field of physics which is made to understand the concept of fluids better ,you may not seek the benefit right now ,but can know the concept,and the application of it in

What is the angle of refraction in the flint glass, A piece of flint glass ...

A piece of flint glass is lying on top of a container of water (see figure below). When a red beam of light in air is incident upon the flint glass at an angle of 28°. What i

Types of rectifier, Types of Rectifier: Half wave Rectifier: The h...

Types of Rectifier: Half wave Rectifier: The half wave rectifier allows positive half cycle of alternating current to pass through the circuit but negative half cycle is s

Magnetic , #questionMnS is a paramagnetic solid. At 300°K, there are 4 × 10...

#questionMnS is a paramagnetic solid. At 300°K, there are 4 × 1022 molecules of MnS per cm3. If the cationic magnetic moment of MnS is 5 MB, use the Curie law in 8-b to compute the

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