# NEET Physics Mechanical Properties of Fluids Questions Solved

Radius of a soap bubble is 'r', surface tension of soap solution is T. Then without increasing the temperature, how much energy will be needed to double its radius

(a) $4{\mathrm{\pi r}}^{2}\mathrm{T}$                        (b) $2{\mathrm{\pi r}}^{2}\mathrm{T}$

(c) $12{\mathrm{\pi r}}^{2}\mathrm{T}$                       (d) $24{\mathrm{\pi r}}^{2}\mathrm{T}$