1000 small water drops each of capacitance c. join Together to form one large spherical drop. the capacitance of the bigger sphear is?

1 Answer
Mar 21, 2018

Volume of single big drop = Volume of 1000 small drops

4/3 pi R^3=(4/3pi r^3)xx1000
where R is the radius of big drop and r is the radius of small drop.
=>R=root (3)(1000r^3)
=>R=10r ........(1)

We know that electric potential on surface of sphere (drop) is

V_s=kq/r
where k is Coulomb's Constant

Comparing with Q=CV
we have

c=q/V_s=q/(kq/r)=r/k ......(2)

Similarly Capacitance of big drop C_b=R/k ........(3)

From (2) and (3) we have

C_b/c=R/r

Using (1) we get

C_b/c=(10r)/r
=>C_b=10c