A) 102 dyne
B) 104 dyne
C) 105 dyne
D) 106 dyne
Correct Answer: C
Solution :
The shape of water layer between the two plates is shown in the figure. Thickness d of the film = 0.12 mm = 0.012 cm Radius R of the cylindrical face \[=\frac{d}{2}\] Pressure difference across the surface \[=\frac{T}{R}=\frac{2T}{d}\] Area of each plate wetted by water = A Force F required to separate the two plates is given by F = pressure difference x area\[=\frac{2T}{d}A\] Putting the given values, we get\[F=\frac{2\times 75\times 8}{0.012}={{10}^{5}}\,dynes\]You need to login to perform this action.
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