MCQ
A drop of liquid of diameter $2.8\, mm$ breaks up into $125$ identical drops. The change in energy is nearly ........ $erg$ (S.T. of liquid = $75\, dynes/cm$)
- A$0$
- B$19$
- C$46$
- ✓$74$
✓
Answer
Correct option: D.
$74$
d
(d) $E = 4\pi {R^2}T({n^{1/3}} - 1)$
(d) $E = 4\pi {R^2}T({n^{1/3}} - 1)$
= $4 \times 3.14 \times {(1.4 \times {10^{ - 1}})^2} \times 75({125^{1/3}} - 1)$$ = 74\;erg$
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