Q. 215.0( 1 Vote )

Two large conducting plates are placed parallel to each other with a separation of 2.00 cm between them. An electron starting from rest near one of the plates reaches the other plate in 2.00 microseconds. Find the surface charge density on the inner surfaces.

Answer :


Given:


Distance travelled by the electron=2cm=2× 10-2m=s


Time taken by the electron =2μs=2× 10-6s=t


Let the surface charge density of the plate be σ


Let the acceleration of electron be a



Using 2nd law of motion



Where,


u=initial velocity


t=time taken to travel


a=acceleration of particle


s=displacement of particle


it is given that electron starts from rest u=0




This acceleration is provided by the force due to electric field between plates


Force applied to the particle is given by


…(i)


Where,


m=mass of electron=9.1× 10-31kg


this force is provided by the electric field (E) between the plates which is given by


…..(ii)


Equating eqns.(i) and (ii)


..(iii)


We know that


Electric field due to a conducting plate of surface charge density σ is given by



Putting this value of E in eqn.(iii)




Putting values of s, m, t and q


C/m2


C/m2


Therefore the surface charge density of the plate is given by


0.503× 10-12C/m2


Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Kirchoff's Law for VoltageFREE Class
All About Faraday's law55 mins
Few Applications of Gauss's law54 mins
Kirchoff's current & Voltage lawFREE Class
Kirchoff's Voltage Law41 mins
Questions based on Kirchoff's Law for Voltage67 mins
Learn Raoult's Law56 mins
Ohm's Law - Full Concept in one Go59 mins
NCERT Important Questions of Gauss's Law43 mins
Interactive Quiz on Kirchoff's Law38 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses
RELATED QUESTIONS :