question_answer

A capillary tube is immersed vertically in water and the height of the water column is x. When this arrangement is taken into a mine of depth d, the height of the water column is y. If R is the radius of earth, the ratio\[\frac{x}{y}\]is:                                [JEE ONLINE 09-04-2014]

A) \[\left( 1-\frac{d}{R} \right)\]

B)      \[\left( 1-\frac{2d}{R} \right)\]

C) \[\left( \frac{R-d}{R+d} \right)\]  

D)      \[\left( \frac{R+d}{R-d} \right)\]

Correct Answer: A

Solution :

[a]

Acceleration due to gravity changes with the depth,

Pressure,

Hence ratio, is