Solveeit Logo
Login

Question

Question: The work done in increasing the size of a soap film from 10cm × 6cm to 10cm × 11cm is ![](https://cd...

The work done in increasing the size of a soap film from 10cm × 6cm to 10cm × 11cm is . The surface tension of the film is

A

1.5×10−2Nm−11.5 \times 10 ^ { - 2 } \mathrm { Nm } ^ { - 1 }

B

3.0×10−2Nm−13.0 \times 10 ^ { - 2 } \mathrm { Nm } ^ { - 1 }

C

6.0×10−2Nm−16.0 \times 10 ^ { - 2 } \mathrm { Nm } ^ { - 1 }

D

11.0×10−2Nm−111.0 \times 10 ^ { - 2 } \mathrm { Nm } ^ { - 1 }

Answer

3.0×10−2Nm−13.0 \times 10 ^ { - 2 } \mathrm { Nm } ^ { - 1 }

Explanation

Solution

∴W=T×2ΔA\therefore W = T \times 2 \Delta A

⇒W=T×2×(A2−A1)\Rightarrow W = T \times 2 \times \left( A _ { 2 } - A _ { 1 } \right)

⇒ T=W2×50×10−4=3×10−42×50×10−4=3×10−2T = \frac { W } { 2 \times 50 \times 10 ^ { - 4 } } = \frac { 3 \times 10 ^ { - 4 } } { 2 \times 50 \times 10 ^ { - 4 } } = 3 \times 10 ^ { - 2 }N/m