23u cant use gauss law as it is nonconducting
2007 IIT-JEE question
Q- A spherical portion has been removed from non-conducting solid sphere having charge uniformly distributed in its volume as shown in the figure.The electric field inside the emptied space is
(A) zero everywhere (B)non zero and uniform (C) non uniform
(D) zero only at its centre.
the answer is (b)
doing it by gauss's law total charge in cavity is zero and by drawing a gaussain surface inside we can see that E inside must be zero.
plzz explain where is the mistake??
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7 Answers
1Gauss's Law doesnot fail here.
I will give you a hint. E will not be 0 because the Gaussian surface just inside the cavity is not symmetric (charge will be 0 though)
1@ pritishmasti gauss law doesn't fail here, suppose that you have drawn a gaussian surface inside the sphere , ( smaller one) then there can be 2 cases when net flux through gaussian surface is zero, first one when charge enclosed is zero and second when field is uniform and number of field lines entering the surface is equal to the number of field lines leaving it.
23yes i m wrong there didnt think think twice
∫E.dA = 0 doesnt imply E = 0
also since it is nonconducting there wont be any rearrangement of charges
u can find out E at a pt in the cavity
E =Edue to original sphere + E of an imaginary sphere same as that removed frm cavity and in the place of cavity , with charge negative of that removed