Question

Why are mercury manometers used for measuring arterial blood pressures instead of water manometers?

a) Mercury has lower density.
b) Mercury has higher density.
c) Water is toxic.
d) Water has higher viscosity.

Answer 1

Mercury manometers are used over water manometers because mercury's higher density allows for a more compact device that is practical for measuring arterial blood pressure.

The Correct option is; b) Mercury has higher density.

Step-by-step explanation:

Mercury manometers are used for measuring arterial blood pressures rather than water manometers primarily due to the higher density of mercury.

This higher density means that the column of mercury in the manometer does not need to be as tall as a column of water to measure the same pressure, making the device more practical and easier to use.

If water, which has a much lower density compared to mercury, were used, the manometer would have to be more than 30 feet tall to measure typical atmospheric pressures, let alone arterial blood pressures which are much lower than atmospheric pressures. Hence, mercury manometers allow for the construction of much more compact devices suitable for medical use.

Mercury manometers are used over water manometers because mercury's higher density allows for a more compact device that is practical for measuring arterial blood pressure.