Properties Of Solids And Liquids Question 204
Question: A large number of water drops each of radius r combine to have a drop of radius R. If the surface tension is T and the mechanical equivalent of heat is J, then the rise in temperature will be[MP PET 1994; DPMT 2002]
Options:
A) $ \frac{2T}{rJ} $
B) $ \frac{3T}{RJ} $
C) $ \frac{3T}{J}\left( \frac{1}{r}-\frac{1}{R} \right) $
D) $ \frac{2T}{J}\left( \frac{1}{r}-\frac{1}{R} \right) $
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Answer:
Correct Answer: C
Solution:
Rise in temperature,$ \Delta \theta =\frac{3T}{JSd}\left( \frac{1}{r}-\frac{1}{R} \right) $ $ \Delta \theta =\frac{3T}{J}\left( \frac{1}{r}-\frac{1}{R} \right) $ (For water S = 1 and d = 1)
