Twenty seven drops of same size are charged at 220V each. They combine to form a bigger drop. Calculate the potential of the bigger drop.

Options

A. 1320 V
B. 1520 V
C. 1980 V
D. 660 V

Answer

C

Explanation

`4/3 pir_2^3 =27 (4/3 pir_1^3)implies r_2 =3r_1 " "....(i)`
`V=(Kq)/rimplies V_1/V_2=((q_1)/q_2)(r_2/r_1)`
`implies 220/V_2=(q/(27q))((3r)/r)implies 200/V_2=1/9`
`implies V_2 = 220 xx 9 = 1980 V`