Question

A decrease in height of a column in a mercury barometer means that

Answer 1

atmospheric pressure decreases

Step-by-step explanation:

A barometer is an instrument which is used to measure atmospheric pressure. The rise or fall in height of column of mercury indicates the pressure.

P = ρgh

where,
`\rho` is the density, g is the acceleration due to gravity and h is the height of the column.

An increase in the height of the column means increase in atmospheric pressure while a decrease in the height of the column means a decrease in atmospheric pressure.

Answer 2

A decrease in height of a column in a mercury barometer means that the air pressure is decreasing. Barometer is a device used to measure atmospheric pressure and also it may be used to measure altitude since atmospheric pressure changes with distances above sea level. Air pressure pushes down on the surface of the mercury, making some rise up the tube, the greater the air pressure, the higher the mercury rises.