Q. 10 cm long wire is placed horizontally on the surface of water and is gently pulled up with a force of $2 \times 10^{- 2}$ N to keep the wire in equilibrium. The surface tension of water in $Nm^{- 1}$ is
A) 0.002
B) 0.001
C) 0.2
D) 0.1
Explanation
(d) $2\ Sl = F$
Or $S = \frac{F}{2l} = \left( 2 \times 10^{- 2} \right)/2 \times 0.10 = 0.1\ Nm^{- 1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.