question_answer

                A thin tube sealed at both is 100 cm long. Itlies horizontally, the middle 20 cm contacting mercury and two equal ends containing air at standard atmospheric pressure. If the tube is now turned to a vertical position, by what amount will the mercury be displaced?                                                 (Given: cross section of the tube can be assumed to be uniform)     [JEE Main Online Paper ( Held On 23  April 2013 )

A)                   2.95 cm                              

B)                                          5.18 cm

C)                                          8.65 cm                              

D)                                          0.0 cm