NEET-XI-Physics
exam-2 year:2016
- #125A rectangular film of liquid is extended from
(4 cm X 2 cm) to (5 cm X 4 cm). If the work done
is 3 X ``10^{-4}`` J, the value of the surface tension of the
liquid is :-
(1) 0.2 ``Nm^{-1}``
(2) 8.0 ``Nm^{-1}``
(3) 0.250 ``Nm^{-1}``
(4) 0.125 ``Nm^{-1}``digAnsr: 4Ans : (4)
Sol. W = T(2▵A) {▵A = (20 - 8) cm2 }
&implies;
W
T
2 A
=
▵
4
1
4
3 10
0.125 Nm
2 12 10
= =
15