A soap film supports 2.4×10−2N over a 48cm slider. What is the surface tension?
S = F2l. F = 2.4×10−2N, l = 0.48m. S = 2.4×10−22×0.48 = 0.025N/m. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 0.025 N/m. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.