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 , 14 Years ago

Grade 12

13 Answers

Sanandanan M

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.

Last Activity: 14 Years ago

G Narayana Raju

i am sorry that was the correct ans

Last Activity: 14 Years ago

sofie sajad

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

Last Activity: 9 Years ago

Abhishek Ranjan

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.

Last Activity: 8 Years ago

Sohan Js

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.

Last Activity: 8 Years ago

Deepak

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

Last Activity: 8 Years ago

Zuhaib

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

Last Activity: 7 Years ago

Yash

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

Last Activity: 7 Years ago

mohit

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

Last Activity: 7 Years ago

Krish Gupta

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.

Last Activity: 5 Years ago

Krish Gupta

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.

Last Activity: 5 Years ago