A) Double
B) Slightly less than double
C) Slightly less than four times
D) Slightly more than four times
Correct Answer: C
Solution :
[c] work done to form a bubble of radius R \[{{W}_{1}}=8\pi {{R}^{2}}{{T}_{1}}\] Work done to form a bubble of radius 2R \[{{W}_{2}}=8\pi {{(2R)}^{2}}{{T}_{2}}=32\pi {{R}^{2}}{{T}_{2}}\therefore \frac{{{W}_{1}}}{{{W}_{2}}}=\frac{{{T}_{1}}}{4{{T}_{2}}}\] If surface tension of soap solution is same, then \[{{W}_{2}}=4{{W}_{1}}\] But in the problem the temperature of solution is increased, so its surface tension decreases. \[\therefore {{W}_{2}}<4{{W}_{1}}\]You need to login to perform this action.
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