BITSAT 2015 Paper

Water wets glass and so the angle of contact is zero.
For full rise, neglecting the small mass in the meniscus
2πrT = pr2hρg ⇒ h =

2T

rρg

[Since water wets glass, θ = 0°]
=
As the tube is only 2 cm above the water and so, water will rise by 2 cm and meet the tube at an angle such that,
2πrT cos θ = πr2h′ρg
⇒ 2T cos θ = h'rρg
⇒ cos θ =

h′rρg

2T

=
The liquid will meet the tube at an angle, θ = 70°