A barometer tube reads 76 cm of mercury. if the tube is gradually inclined keeping the open end immersed in the mercury reservoir, will the length of mercury column be 76 cm, more than 76 cm or less than 76 cm?

The vertical length(l) of the mercury column depicts the pressure and thus for a particular pressure is fixed.


If we tilt the tube, the pressure being the same, the length of the mercury may increase as given by:



As cos

1