A barometer gives false readings because a small amount of a

A barometer gives false readings because a small amount of air has been trapped above the mercury column. At pressure of 755mm, it reads 748mm; 740mm, it reads 736mm,

Suppose this space is made to be 200 cm3 and the same amount of air has collected above the mercury. What will be the percentage error when the true barometric pressure is 755mm?

Solution

since at 755 mm , it reads 748, Percentage error = (748-755)x100/755=0.93%