15-01-09. Charged Shells

Suppose that there are 3 concentric metallic shells placed inside each other.. (radius r, 2r, 4r respectively)

the outermost is given a charge Q

The middle shelll has q charge

What is the charge that flows if The outermost shell is connected to the innnermost shell..
also tell the direction.

25 Answers

62
Lokesh Verma ·

see i am sleeping.. sorry for confusing u all.. it wont be 3q :)

But it wont contain Q either... (sorry subash i will check it :)

62
Lokesh Verma ·

oh i din see gagar's answer.. will check that one :)

62
Lokesh Verma ·

but they will come back :)

1
skygirl ·

wow! pink!

:P

tx.

well bhaiya... delete that pink in vapour pressure question...

woh wrong tha...

gagar answered it ...

62
Lokesh Verma ·

good work sky :)

1
skygirl ·

:( :( :(

jiske liye banayi .... woh chale gaye :(

[3]

1
skygirl ·

3
msp ·

but u have given that there is a charge x that flows from the outer shell to the inner shell and u didnt mentioned that x charge is induced

62
Lokesh Verma ·

no in the inner surface of the innermost shell, there is no induced charge..

3
msp ·

will there be no charged induced on the inner shell

1
skygirl ·

pot at outermost shell = (Q+q+q')/4r

pot at innermost = (4q'+2q+Q)/4r

wen we join these two..

both pot will be same.

so, q'= - q/3

so charge on innersphere= -q/3.

chare on outer = Q+2q/3.

hence charge transfered : q/3.

from outer sphere to inner sphere.

1
skygirl ·

outermost one.... will be Q+q '+' x naa ?

62
Lokesh Verma ·

lets first see the charge distributions

innermost: 0, x (x flows from outermost to innnermost)

Middle: -x, q+x

Outermost: -q-x, Q+q+x (edited)

This will be the charge distribution...

Can u see this and then try to find the value of x?

62
Lokesh Verma ·

Of course intelligent minds think similar :P :D

dont blame me of plagiarism

11
Subash ·

i seriously think im sleeping cos third ans im giving today

-4q/3

1
°ღ•๓яυΠ·

is it Q

1
°ღ•๓яυΠ·

m gettin it as Q

n ya solly pura q ni padha tha bhayah ...........hcv q is diffrnt there d middle one is earthed n u just gt to find d charge distribution

11
Subash ·

sorry i dint see ur posts

i got it equal to q

11
Subash ·

taking the charge on outer to be Q-q2

and innermost to be q2

and then equating the potentials on the surface of innermost and outermost shells because they are connected

62
Lokesh Verma ·

subash I dont think it should have the term for Q!

62
Lokesh Verma ·

This hint is simple sankara..

1) You have to use gauss' law in the metallic part of the shells

2) Potential fo the outer shell is equated to that of the innermost shell...

3
msp ·

ok wat abt giving solns or hints....

62
Lokesh Verma ·

i can say that about many of the question of the days.. ;)

if they are at some other place.. dont blame me for that :P

11
Subash ·

so do u say that u made this q on ur own

62
Lokesh Verma ·

and yeah dont blame me of self praise either :D ;)

I know that i do that a lot.. but then dont blame me for it ;)

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