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A frame made of metalic wire enclosing a surface area A is covered with a soap film. If the area of the frame of metallic wire is reduced by `50%` the energy of the soap film will be changed by:A. `100%`B. `75%`C. `50%`D. `25%` |
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Answer» Correct Answer - C Surface energy = surface tension `xx` surface area `E=Txx2A` New surface energy, `E_(1)=Txx2((A)/(2))=TxxA` % decrease in surface energy `=(E-E_(1))/(E)xx100` `=(2TA-TA)/(2TA)xx100=50%` |
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