# Forum

Twenty-seven drops ...

Clear all

# 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.

0
Topic starter

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) 660 V

(2) 1320 V

(3) 1520 V

(4) 1980 V

Topic Tags
0

Explanation:

$$\frac{4}{3}\pi R^3$$ = 27$$(\frac{4}{3}\pi r^3)$$ ⇒ R = 3r   .....(1)

V = $$\frac{Kq}{r}$$ ⇒ $$\frac{V_1}{V_2}$$ = $$(\frac{q_1}{q_2})$$$$(\frac{r_2}{r_1})$$

⇒ $$\frac{220}{V_2}$$ = $$(\frac{q}{27q})$$$$(\frac{3r}{r})$$

⇒ $$\frac{220}{V_2}$$ = $$\frac{1}{9}$$

⇒ V2 = 220 x 9 = 1980 volt

Share: