1. The problem statement, all variables and given/known data A wire forming a loop is dipped into soap solution and taken out so that a film of soap solution is formed. A loop of 6.28 cm long thread is gently put on the film and the film is pricked with a needle inside the loop. The thread loop takes the shape of a circle. Find the tension in the thread. Surface tension of soap solution = 0.030 N/m 2. Relevant equations 3. The attempt at a solution First i found the the radius of the loop which is 1cm. I drew below diagram. I wrote eqn 2Tsin(dϑ)=2*(S*2Rdϑ) where T is tension and S is surface tension. I multiplied the RHS by 2 because soap solution has two layers. But by solving this i am getting answer 6×10-4 but my book says answer is 3×10-4. Please tell me where i am wrong ??