Electric Current> relaxation time...

what is relaxation time?derive an expression for resistivity of a wire in terms of member density of free electrons and relaxation time.

G Narayana Raju , 13 Years ago

Grade 12

13 Answers

Sanandanan M

Last Activity: 13 Years ago

Relaxation time is the time interval between two successive collisions of electrons in a conductor, when current flows.
I = nave --> n->no. of free electrons a->area of conductor v->drift velocity e->charge of electron
but v=(eE/m)T--> E-> field m->mass of electron T->Relaxation time
From this, you can find expression of relaxation time.Field is V/length and V=IR.From this you can modify the expression in terms of resistivity.

G Narayana Raju

Last Activity: 13 Years ago

i am sorry that was the correct ans

sofie sajad

Last Activity: 8 Years ago

Relaxation time is actually a time constant that describes the rate of decay of charges inside the conductor.

Abhishek Ranjan

Last Activity: 8 Years ago

Let us suppose that we have a solid metal ball or sphere and you placed a charge inside it. This charge will arrive at the surface as a surface charge. How fast this charge arrives at the surface can be calculated by using the term relaxation time.
The charge we kept inside the ball repel each other to arrive at the surface. Time taken by charges to travel to the surface s represented by relaxation time.

Sohan Js

Last Activity: 7 Years ago

If Electric field is turned OFF suddenly the average velocity decreases exponentially. The decay of average velocity is given by

v_avg =v_avge^-t/t_r

At t=t_r

v_avg=v_avge^-1

Relaxation time can be defined as the time taken by electron to attain an average velocity which is 1/e times its value.

Deepak

Last Activity: 7 Years ago

Relaxation time :It is the time between 2 successive collisions of an electron with atoms/ions of the conductor

Zuhaib

Last Activity: 6 Years ago

The average time interval between two successive collisions is called relaxation time of electrons.

Yash

Last Activity: 6 Years ago

The average time between successive collison of an electron is called relaxation time . During the relaxation time ,electron gain average velocity.

mohit

Last Activity: 6 Years ago

average time taken by electron to attain steady state from zero velocity in presence o electric field.

Krish Gupta

Last Activity: 5 Years ago

If Electric field is turned OFF suddenly the average velocity decreases exponentially. The decay of average velocity is given by

v_avg =v_avge^-t/t_r

At t=t_r

v_avg=v_avge^-1

Relaxation time can be defined as the time taken by electron to attain an average velocity which is 1/e times its value.

Krish Gupta

Last Activity: 5 Years ago

You can think it intuitively as well.Let us suppose that we have a solid metal ball or sphere and you placed a charge inside it. This charge will arrive at the surface as a surface charge. How fast this charge arrives at the surface can be calculated by using the term relaxation time.The charge we kept inside the ball repel each other to arrive at the surface. Time taken by charges to travel to the surface s represented by relaxation time.