Manometer & related problems

The diagram shows a manometer connected to the gas supply and the level of mercury in the left hand limb rises.

Given that the pressure of the gas supply and atmospheric pressure are 50 cm Hg and 76 cm Hg respectively, what is the height of the mercury column above point A?

• 16 cm

• 26 cm

• 50 cm

• 76 cm

The diagram shows a manometer connected to a vacuum pump.

Initially, the mercury levels were even between the two limbs. When the vacuum pump is turned on, it removes a portion of the air in the left hand limb.

The dotted lines are the initial mercury levels of each limb.

Which of the following diagrams shows the likely mercury levels in both limbs after the vacuum pump is turned on?

• 
• 
• 
• 

The diagram shows a manometer connected to a gas supply and the level of the mercury in the right hand limb rises.

Given that the atmospheric pressure is 76 cm Hg, what is the pressure of the gas supply?

• 20 cm Hg

• 21 cm Hg

• 35 cm Hg

• 111 cm Hg

The diagram shows a manometer connected to a gas supply and the level of the mercury in the left hand limb rises.

The pressure of the gas supply and atmospheric pressure are 40 cm Hg and 76 cm Hg respectively.

What is the pressure at point A?

• 30 cm Hg

• 40 cm Hg

• 76 cm Hg

• 116 cm Hg

The diagram shows a manometer of uniform cross-sectional area.

The shaded region is filled with liquid F while the unshaded region is filled with water.

Given that the density of liquid F and water are 530 kg/m³ and 1000 kg/m³ respectively, what is the height of the water column above point A?

• 30.0 mm

• 33.0 mm

• 35.0 mm

• 53.0 mm