1thx a lot sir.............
i didn expect d solution to be lik dis n dis method too.................;-)
Consider two solid spheres A and B made up of a linear and homogeneous dielectric, each having a radius a. Their centers are separated by a distance r\gg a. The sphere A carry a charge +q while B is neutral. Now if all the linear dimensions of the system are scaled by a factor of 2, what charge must reside on A for the force between the spheres to remain the same?
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25 Answers
1ThnQ very much sir
I got the first statement but the remaining went wrong
A different aspect of attraction of charges
1
66okay here's the solution. First note that the dipole moment induced in a linear dielectric is proportional to the external field in which it is kept. So the dipole moment induced in B
p_B \propto \dfrac{q}{r^2}
Further, the net force on a dipole is proportional to the product of the dipole moment and the rate at which the electric field changes along the length of the dipole. Hence,
F\propto \dfrac{p_Bq}{r^3}\propto \dfrac{q^2}{r^5}
The condition that F=F^\prime after increasing the linear dimensions by 2, gives the new charge q^\prime as
\dfrac{q^2}{r^5}=\dfrac{{q^\prime}^2}{{r^\prime}^5}
that is \dfrac{{q^\prime}^2}{q^2}=2^5=32
Hence, q^\prime=q\sqrt{32}=4\sqrt{2}\,q
66the answer is not .5q or 16q. And the spheres are given to be made of dielectric material. But they are kept in air.
1I think V assume it to be present throughout the gap.
So its thickness would be r-2a≈r
1I think V assume it to be present throughout the gap.
So its thickness would be x-2a≈x
1thickness of d dielectric has to be given i think........................
1@ Ram
Yes there will be a force due to q, Bis a dielectric.
But I dont think V can directly use Coloumbs law[2][2]
1WONT THERE B A FORCE DUE TO +q charge?????????
i think i made a mistake
1B is neutral!!!!!!!!!!!!!!
Ramkumar did U take that into consideration???
1sir, ur profile photo is nice .........
but wen we go wron in answering a question n see it ,
its lik laughing at us dat we don kno dis too......... ;-)
jus fr fun;-)
1if u ve meant dat as divided ur ans must be rit..
i too did it......
of course i think we r correct...
kaymant sir, is d ans +2q?????
scaled down??????????????
1Charge=2q[7][7]
Does scaled by a factor of 2 mean multiplied or divided by two
1sir,
we ve to find dis jus by equating d forces in two cases or.................?????????????/