question_answer

A barometer tube reads 76 cm of mercury. If the tube is gradually inclined at an angle of 60o with vertical, keeping the open end immersed in the mercury reservoir, the length of the mercury column will be

A)            152 cm                                    

B)            76 cm                                      

C)            38 cm                                      

D)            \[38\sqrt{3}cm\]

Correct Answer: A

Solution :

                   \[\cos 60{}^\circ =\frac{h}{l}\] Þ\[l=\frac{h}{\cos 60{}^\circ }=\frac{76}{1/2}\]            \ \[l=152\ cm\]