Question:
A thin flat circular disc of radius 4.5 cm is placed gently over the surface of water. If surface tension of water is 0.07 Nm-1, then the excess force required to take it away from the surface is :
A thin flat circular disc of radius 4.5 cm is placed gently over the surface of water. If surface tension of water is 0.07 Nm-1, then the excess force required to take it away from the surface is :
Updated On: Dec 9, 2024
- 19.8 mN
- 198 N
- 1.98 mN
- 99 N
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The Correct Option is A
Solution and Explanation
Excess force is calculated as:
F = 2πr · T = 2π(0.045)(0.07) = 19.8 mN.
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