38. The force required to separate two glass plates of area
The force required to separate two glass plates of area 10-2m2 with a film of water 0.05 mm thick between them, is (Surface tension of water is 70 x 10-3 N/m)
(a) 28 N
(b) 14 N
(c) 50 N
(d) 38 N
Ans. a
(19)