Question

A film of water is formed between two straight parallel wires each 0.1 m long and at a separation of $5\times 10^{-3}m$. calculate the work required to increase $1 \times 10^{-3}m$ distance between wires ( surface Tension of water = 0.072N/m )

• A. $14.4 \times 10^{-5}J$
• B. $1.44 \times 10^{-5}J$
• C. $144 \times 10^{-2}J$
• D. 144J

Answer 1

Answer: (B)

$1.44 \times 10^{-5}J$

Answer 2

$W = TX \, \Delta 4$