3) There are infinite point charges of equal charge Q and placed along x-axis at x=1,x=2,....x= (2)n
If v remove charge at x=4 , then potential at x=0 due to rest of charges is
a) Q/Πξ
b)Q/2πξ
C)7q/32πξ
d)9Q/48πξ
CONCEPTUAL
A point charge Q1 is placed at the centre of an uncharged conducting shell and another point charge Q2 is placed outside the shell at distance r from its centre
Then explain the forces on both the charges and their distribution ?
241st one is easy
Viinitial=kQ/r1 +kQ/r2 +kQ/r3 +......∞
=> KQ[1/r1 +1/r2 +1/r3+...∞]
[1/r1 +1/r2 +1/r3+...∞] is an infinte GP
let its value be S
so,Viinitial=KQ.S
Finally Vfinal=KQ/r1 +KQ/r2+KQ/r4 +....∞
Vfinal=(kQ/r1 +kQ/r2 +kQ/r3 +......∞)-KQ/r3
Vfinal=KQ.S- KQ/r3
242nd one
Q1 will induce charge on inside of shell
and Q2 will also induce charge on outer surface.but net charge on shell remains zero
There wont be any force b/w Q1 and Q2 becoz condicting shell..so electric field lines from Q2 will have to terminate outside shell..same with Q1 electric field lines
