My Infinite Conductor!

Electricity and Magnetism Level 5

As shown in the diagram above, there is a system of 2 charges of opposite signs and equal magnitude $Q = 1 \mu C,$ placed over an infinitely extending grounded conductor.

Find the electrostatic potential energy (in Joules) of the system.

This is a part of my set Aniket's Electrostats Challenges

The answer is -0.9475.

1 solution

A Former Brilliant Member
Mar 7, 2017

Relevant wiki: Conservative nature of Electric fields

uh-oh ! MOTHER of over-rated stuff spotted :P just use image charge theory was getting exactly twice as U i.e -1.895 and half it as the Electric field on the down side of conductor is 0 but while using image charges we calculated electric field for that part also so we have to half our answer by image charges. pic by @mention[295232:Rahul Kumar] pic by @Rahul Kumar

Can you write a solution that is helpful to those who cannot solve it? Else I'm inclined to delete this solution to encourage others to contribute a relevant answer.

R G Staff - 4 years, 3 months ago

don't u think it's helpful ?

A Former Brilliant Member - 4 years, 3 months ago

No, the person who is not able to solve this problem will not be able to understand what is the meaning of "image charge theory" from your solution. Also, it is not clear that how you get the value of potential energy $U = -1.895$ . So, it will be really great if you can fill in those gaps and elaborate on it.

R G Staff - 4 years, 3 months ago

@R G – yes sir, i'll surely do it after physics exam my phone will be repaired by then. i'll upload a pic:)

A Former Brilliant Member - 4 years, 3 months ago

@A Former Brilliant Member – Thank you, That will be really helpful for the community.

R G Staff - 4 years, 3 months ago

ok now sir ?

A Former Brilliant Member - 4 years, 3 months ago

Yes, I think it is very helpful. Thanks to both of you.

R G Staff - 4 years, 2 months ago

https://goo.gl/photos/cakBycppYXDQH7Qr7 -see my solution here. I was unable to post because i figured it out later after giving wrong answer.

Rahul Kumar - 4 years, 3 months ago

thnx , u saved me much trouble of repairing my fone :P

A Former Brilliant Member - 4 years, 3 months ago

Why is the energy being halved??

Shubhendra Singh - 4 years, 2 months ago

The level is because many people don't know image charge method as it is not in JEE syllabus , I too myself learnt it some days back!

Aniket Sanghi - 4 years, 3 months ago

Could u post a solution for ur other image theory problme where we needed to find the time to collide

Zerocool 141 - 4 years, 1 month ago

May be if I can Find time . This is JEE Time.....

Aniket Sanghi - 4 years, 1 month ago

@Aniket Sanghi – Yeah actually! We all learnt it from Youtube!

Md Zuhair - 3 years, 2 months ago

My Infinite Conductor!

This is a part of my set Aniket's Electrostats Challenges

The answer is -0.9475.

1 solution

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