A cyclindrical vessel of height 500 mm has an orifice (small hole) at its bottom. The orifice is initially closed any water is filled in ti upto height H.Now the top is completely sealed with a cap and the orifice at the bottom is opened .Some water comes out from the orifice and the water level in the vessel becomes steady with height of water column being 200mm. The fall in height (in mm) of water level due to opening of the orifice is [ Take atmospheric pressure = `1.0 xx 10^(5) N/m^(2)`, density of water = `1000 kg/m^(3)`. Neglect any effect of surface tension.]

Answer

6

Explanation

`P_(0) =` atmospheric pressure
`P + 200 xx 10^(-3) xx 1000 xx 10 = P_(0) ……(1)`
`P_(0)(500 - H) = P . (300 mm)`
`rArr P = (P_(0)(500 - H)mm)/(300mm) …..(2)`

From `(1)` and `(2)`
`(P_(0)(500 - H))/(300) + 2000 = P_(0)`
`(10^(5)(500 - H))/(300) + 2000 = 10^(5)`
`rArr 5 xx 10^(7) - H xx 10^(5) + 6 = 300`
`rArr H = 206mm`
`H = 206 mm`
fail in height `= 6 mm`