Question

# Two communicating vessels contain mercury. The diameter of one vessel is n times larger than the diameter of the other. A column of water of height h is poured into the left vessel. The mercury level will rise in the right-hand vessel(s = relative density of mercury and ρ = density of water) by

A

B

C

D

Solution

## The correct option is A If the level in narrow tube goes down by h1 then in wider tube goes up to h2, Now, πr2h1=π(nr)2h2⇒h1=n2h2 Now, pressure at point A = pressure at point B hρg=(h1+h2)ρ′ g ⇒h=(n2h2+h2)sg(As s=ρ′ρ)⇒h2=h(n2+1)s

Suggest corrections