Question

By sucking through a straw, a student can reduce the pressure in his lungs to $750\, mm$ of $Hg$ (density $= 13.6\, g/cm^3$ ). Using the straw, he can drink water from a glass upto a maximum depth of

• A. 10 cm
• B. 75 cm
• C. 13.6 cm
• D. 1.36 cm

Answer 1

Answer: (C)

13.6 cm

Answer 2

Pressure difference between lungs of student and atmosphere $=(760-750) \,mm$ of $Hg$ $hdg =10\, mm$ of $Hg =1\, cm$ of $Hg$ or $h \times 1=1 \times 13.6$ $\therefore \,h =13.6 \,cm$