Question

If an air bubble rises from the bottom of a
mercury tank to the top its volume becomes
1 times. When normal pressure is 76cm of
Hg then the depth of the Hg tank is
1/ 38 cm
38 cm 2) 132 cm 3) 76 cm 4) 49 cm
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Answer 1

et the height be h

pressure at the bottom = h + 76 (atmospheric pressure)

now as it reaches at the top, pressure = 76 (only atmospheric pressure now)

at constant temperature we can apply Boyle's law

here P1  = h + 76

P  2   = 76

V2  =  3 \2 V1

so,we get P1V1=P2V2

on solving this gives h = 38 cm

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