Question

I got this question online from the link:http://hkpho.phys.ust.hk/Training/Assignments/Assignment%209%20-%20Electricity%20&%20Magnetism%203.pdf
I need help in solving it.

Q2
Consider a case with the same geometry as Example-6.
The point charge at x = d is replaced by a point electric
current source (can be viewed as a very small spherical
conductor) held at potential V0. The conductor plate is
still held at V = 0. The rest of the space in x > 0 is filled
with a medium with conductivity σ and dielectric
constant ε. Find the total charge Q on the small
conductor and the total electric current I

Answer 1

Absolutely not sure at all (be careful):
for x<(d-r)
\[V_0=1/(4π.ϵ_0).(Q/r)=>Q=(4π.ϵ_0.r).V_0\]
\[C.R=(Q/V_0).(V_0/I)=Q/I=ϵ.ϵ_0/σ=>I=Q.σ/(ϵ.ϵ_0)=>\]
\[I=(4.π.r.σ/\epsilon).V_0\]