E ~ 1/C ~ 1/R - 1/R°
now
1/R - 1/R° = 1/2R
R° = 2R
- Sharon Amhabjiefbje Sidhusky This will work, but I have a better answer. Should I post my answer?
An isolated conducting sphere of radius R=6.85cm is given a charge of 1.25nC. What is is the radius R_{0} of an imaginary spherical surface such that half of the stored potential energy lies within it ?
Yes, Always charge is conserved. And E is proportional to 1/C.
Testing another answer.Testing another answer.Testing another answer.Testing another answer.
E ~ 1/C ~ 1/R - 1/R°
now
1/R - 1/R° = 1/2R
R° = 2R
E= Q^{2}/2C
Q is conserved
so E is proportional to 1/C
also u need to know formula for C of spherical surfaces