Question

A manometer reads the pressure of a gas in an enclosure as shown in the figure.

The absolute and gauge pressure of the gas in cm of mercury is

(Take atmospheric pressure = 76 cm of mercury)

• A. 76, 20
• B. 20, 76
• C. 96, 20
• D. 20, 96

Answer 1

Answer: (C)

96, 20

Answer 2

Here atmospheric pressure $\rho = 76$cm of mercury in figure

Pressure head, h = 20 cm of mercury

Absolute pressure = P + h = 76 + 20 = 96 cm of mercury.

Gauge pressure = h = 20 cm of mercury.