Two vertical parallel glass plates are partially submerged in water. The distance between the plates is d and the length is `l`. Assume that the water between the plates does not reach the upper edges of the plates and the wetting is complete. The water will rise to height (`rho=` density of water and `alpha =` surface tension of water)

Options

A. ` (2 sigma )/( rho g d ) `
B. ` ( sigma ) /( 2 rho g d ) `
C. ` ( 4 sigma )/( rho g d ) `
D. ` ( 5 sigma )/( rho g d ) `

Answer

A

Explanation

Pressure difference ` = (sigma ) /(R ) = sigma ((2)/(d)) = ((2 sigma )/(d )) , (2 sigma ) /(d) rho g h rArr h = ((2 sigma )/( rho d g )) `