Twenty seven drops of same size are charged at 220 V each. They combine to form a bigger drop. Calculate the potential of the bigger drop. (1) 1980 V (2) 660 V (3) 1320 V (4) 1520 V
For each drop, V=kq/r=220 V ⇒q=220r/k Also, Volume of 27 smaller drops = Volume of single drop ⇒27×4/3×πr3=4/3×πR3 ⇒R=3r Further, Q=27q=27×220r/k Potential of bigger drop, V=kQ/R=k/3r×27×220r/k v= 1980 V
