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Physics · PYQ NEET UG 2021
हिन्दीTwenty seven drops of same size are charged at \( 220 \text{ V} \) each. They combine to form a bigger drop. Calculate the potential of the bigger drop.
Correct answer · Option 3
\( 1980 \text{ V} \)
Explanation
Radius of big drop \( R = n^{1/3}r = (27)^{1/3}r = 3r \). Charge \( Q = nq = 27q \). Potential \( V_{big} = \frac{kQ}{R} = \frac{k(27q)}{3r} = 9 (\frac{kq}{r}) = 9 \times 220 = 1980 \text{ V} \).
