NEET 2021 · PhysicsConductor spherePrevious Year Question
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.
Answer: (B) 1980 V. Answer: (b) Solution: Volume conserved → R = n^(1/3) r.
- A.1520 V
- B.1980 V✓
- C.660 V
- D.1320 V
Correct Answer
(B) 1980 V
Solution & Explanation
Answer: (b) Solution: Volume conserved → R = n^(1/3) r. Big charge Q = nq, V_big = kQ/R = k(nq)/(n^(1/3)r) = n^(2/3)(kq/r) = n^(2/3) v = 27^(2/3) × 220 = 9 × 220 = 1980 V. → option (b).
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