Question

A barometer is carried from the $1^{st}$ floor to the ${20}^{th}$ floor of a building. Why does the reading on the barometer fall?

• A. Air pressure has increased
• B. Gravity has decreased
• C. Temperature has increased
• D. There is less air above the barometer

Answer 1

The correct option is D There is less air above the barometer

Answer is D.
The air pressure decreases as the we go up the atmosphere. Therefore, when a barometer is carried from the 1st floor to the 20th floor of a building, the air pressure decreases and hence the reading on the barometer falls down.