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 efficiency of a transformer, Q. What is efficiency of a transformer...

Q. What is efficiency of a transformer? Efficiency of a transformer is described as the ratio of output power to the input power. η= output power / input power

Differential equation for simple harmonic oscillator, Write down Seteps of ...

Write down Seteps of differential equation for simple harmonic oscillator subjected to a damping force proportional to periodic force of angular frequency ω and velocity of oscilla

Rydberg constant, Rydberg constant (Rydberg): A constant that governs ...

Rydberg constant (Rydberg): A constant that governs the relationship of the spectral line features of an atom by the Rydberg formula. For hydrogen, it is about 1.097 x 10 7 m

How far will a force stretch the spring, A certain spring is known to obey ...

A certain spring is known to obey Hooke's Law.  If a force of 10 newtons stretches the spring 2 meters, how far will a 30 newton force stretch the spring? Ans: A certain spr

Define core type transformers, Core type Transformers: In this type of ...

Core type Transformers: In this type of transformer the windings enclose the core (fig. given below). Both the windings are divided and half of every winding is placed on eac

What do you mean by thin prism, What do you mean by thin prism? and What i...

What do you mean by thin prism? and What is the lateral shift given by a parallel sided glass slab for grazing incidence of light?

Determine state when 3 capacitors connected in series, Three capacitors wit...

Three capacitors with different capacitances are connected in series.  Which of the following statements is TRUE? a) All three of the capacitors have the same potential diffe

Explain the shape of the charged particle path, A charged particle is movin...

A charged particle is moving in a UNIFORM magnetic field.  If the direction of motion of the charged particle is parallel to the magnetic field, explain the shape of the charg

Evaluate the path of the magnetic field, A straight vertical wire passes by...

A straight vertical wire passes by a wooden table top. The wire carries an upward directed current. Evaluate the path of the magnetic field of the wire at a point on the table top

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