On increasing the temperature of a conductor, | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) The resistance $R$ of a conductor is given by the formula $R = \frac{ml}{ne^2 	au A}$,where $m$ is the mass of the electron,$l$ is the length,$n$

Vedclass · Accepted Answer

Relaxation time decreases

Vedclass · Answer

(A) The resistance $R$ of a conductor is given by the formula $R = \frac{ml}{ne^2 	au A}$,where $m$ is the mass of the electron,$l$ is the length,$n$ is the electron density,$e$ is the charge,$A$ is the cross-sectional area,and $	au$ is the relaxation time.From this relation,we see that $R \propto \frac{1}{	au}$.When the temperature of a conductor increases,the thermal velocity of the free electrons increases.This leads to more frequent collisions between the electrons and the lattice ions.Consequently,the average time between two successive collisions,known as the relaxation time $	au$,decreases.Since $R$ is inversely proportional to $	au$,a decrease in $	au$ results in an increase in the resistance $R$.

On increasing the temperature of a conductor,its resistance increases because

Similar Questions

Two wires each of radius of cross section $r$ but of different materials are connected together end to end (in series). If the densities of charge carriers in the two wires are in the ratio $1 : 4$,the drift velocity of electrons in the two wires will be in the ratio:

Two identical conductors are kept at the same temperature. If the ratio of the potential difference across them is $1 : 2$,what will be the ratio of their drift velocities?

The mechanism of the heat produced in a conductor when an electric current flows through it can be explained on the basis of

The drift velocity of electrons in a current-carrying wire of radius $r$ is $v$. If we want a drift velocity of $2v$ in a wire of the same material but with half the radius,what current must be passed through it?

The $SI$ unit of the current density is . . . . . . .

Vedclass Test Series

Exam Paper Generator

Online Exam Module