Question

A satellite revolves round the earth. Air pressure inside the satellite is maintained at $76 \,cm$ of mercury. What will be height of mercury column in a barometer tube $100\, cm$ long placed in the satellite?

• A. zero
• B. $76\,cm$
• C. $100\,cm$
• D. none of these

Answer 1

Answer: (C)

$100\,cm$

Answer 2

Inside the satellite , effective value of acceleration due to gravity, $g_{\text{eff}}$ is zero. There will be no pressure difference in side the mercury. Due to which, the mercury will rise to full length of the tube i.e. $100\, cm$, because air pressure outside the tube is $76\, cm$ of mercury, while pressure above the tube is zero.