correct answer is 1. solve showing all steps
Q.9. A massless inextensible string in the form of a loop is placed on a horizontal film of soap solution of surface tension T. If film is pierced inside the loop and it convert into a circular loop of diameter d, then the tension produced in string is
(1) Td
(2) $\mathrm{\pi }$Td
(3) ${\mathrm{\pi d}}^{2}T$
(4) $\frac{{\mathrm{\pi d}}^{2}T}{4}$