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xn_
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Hello,
I'm learning EM from Bleaney & Bleaney and got stuck on Ex2.1 (can do Ex2.2-2.7, though...) - If the polarization charge on the surface of a spherical cavity is -s.cos(theta), prove that the field strength at the centre is s/3e0. If I expand V(r) within the cavity as A.r.cos(theta) + B.r^-2.cos(theta), then I agree B=0 or else V(0) would be singular, but that leaves the A term and surface charge = e0Er = -e0(dV/dr) = -e0A.cos(theta) and hence A = s/e0 not s/3e0 - what am I doing wrong?
Thanks,
Julia
I'm learning EM from Bleaney & Bleaney and got stuck on Ex2.1 (can do Ex2.2-2.7, though...) - If the polarization charge on the surface of a spherical cavity is -s.cos(theta), prove that the field strength at the centre is s/3e0. If I expand V(r) within the cavity as A.r.cos(theta) + B.r^-2.cos(theta), then I agree B=0 or else V(0) would be singular, but that leaves the A term and surface charge = e0Er = -e0(dV/dr) = -e0A.cos(theta) and hence A = s/e0 not s/3e0 - what am I doing wrong?
Thanks,
Julia