If two glass plates have water between them and are separated by very small distance (see figure), it is very difficult to pull them apart. It is because the water in between forms cylindrical surface on the side that gives rise to lower pressure in the water in comparison to atmosphere. If the radius of the cylindrical surface is R and surface tension of water is T then the pressure in water between the plates is lower by :
← JEE Main 2015 · 10 Apr · Shift 1
PhysicsSingle correct+4 / -1Question 9 of 90
JEE Main 2015 · 10 Apr · Shift 1, Physics question 9
Answer and worked solution
Official answer: Bonus: full marks to everyone
A cylindrical surface has one principal radius R and the other infinite, so by the Young-Laplace equation the pressure in the water is lower by .
That is not among the options, and the question was given marks to all.
Topics:Surface tension