JEE Mains 2020 Model Paper 1 New Pattern

Let a water drop of radius R be split up into 109 identical water drops each of radius r.
R =

D

2

=

2mm

2

= 1 mm = 1 × 10−3m
Number of droplets n = 109
Surface tension (T) = 7.3 × 10−2Nm−1W = 4πR2T[n1∕3−1]
= 4π(10−3)2×7.3×10−2[(109)1∕3−1] = 9.1×10−7J