A U -tube in which the cross - sectional area of the limb on the left is one quarter, the limb on the right contains mercury `(density 13.6 g//cm^3).` The level of mercury in the narrow limb is at a distance of 36 cm from the upper end of the tube. What will be the rise in the level of mercury in the right limb if the left limb is filled to the top with water ?

Options

A. 1.2 cm
B. 2.35 cm
C. 0.56 cm
D. 0.8 cm

Answer

C

Explanation

`A_2=4A_1`
Since, Volume remains constant
`A_1 L_1=A_2 L_2`
`implies A_1 L_1=4A_1L_2 implies L_2=(L_1)/(4)`
Pressure at interface
`(36+4L_2)xx1xx g=(5L_2 xx 13.6 xx g)`
`implies L_2=0.56` cm