1.

ff the work done in blowing a bubble of radius R is \W, then the work done in blowing a bubble of radius 2R from that solution is :

Answer»

W/2
2W
4W
`2^(1//3)W`

SOLUTION :Work done = T `xx` increase in area.
`thereforeW_(1)=T.2[4piR^(2)-0]`
`W_(1)=8piR^(2)T.`
& `W_(2)=T.2[4pi(2R)^(2)-0]`
`=32piR^(2)T.`
`THEREFORE(W_(2))/(W_(1))=(32piR^(2)T)/(8piR^(2)T)RARR(W_(2))/(W_(1))=4`
`rArrW_(2)=4W_(1)`
Thus correct choice is (c).


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