Fluid Statics: Pressure, Buoyancy, and Stability in Fluids

Question 1

In a closed cylinder with a piston containing liquid, increasing the pressure on the piston causes the pressure at the bottom of the cylinder to:

Accepted Answer

Increase

Answer

Decrease

Answer

Remain unchanged

Answer

Varies with the volume of the liquid

Question 2

A pipe has a gauge pressure of 60 kPa. If the atmospheric pressure is 101 kPa, the absolute pressure in the pipe is:

Accepted Answer

161 kPa

Answer

41 kPa

Answer

101 kPa

Answer

202 kPa

Question 3

A rectangular water tank with a base length of 2 m and width of 1.5 m has a water depth of 1 m. The force exerted by the water on one vertical wall is:

Accepted Answer

29.4 kN

Answer

14.7 kN

Answer

44.1 kN

Answer

58.8 kN

Question 4

Which of the following factors does NOT affect the buoyant force acting on a submerged object?

Accepted Answer

Shape of the object

Answer

Density of the fluid

Answer

Volume of the displaced fluid

Answer

Acceleration due to gravity

Question 5

Which of the following conditions is necessary for a body to float in equilibrium in a fluid?

Accepted Answer

The weight of the body is equal to the buoyant force.

Answer

The center of gravity of the body is above the center of buoyancy.

Answer

The center of buoyancy of the body is above the center of gravity.

Answer

The body has a uniform density.

Question 6

Which of the following expressions describes gauge pressure in a fluid?

Accepted Answer

Absolute pressure minus Atmospheric pressure

Answer

Atmospheric pressure minus Absolute pressure

Answer

Hydrostatic pressure minus Atmospheric pressure

Answer

Absolute pressure plus Atmospheric pressure

Question 7

Pascal's principle states that:

Accepted Answer

Pressure applied to a confined fluid is transmitted equally in all directions throughout the fluid.

Answer

The pressure at a given point in a fluid is different in different directions.

Answer

The force exerted by a fluid on a submerged object is proportional to the object's density.

Answer

The center of buoyancy is always higher than the center of gravity for stable floating objects.

Question 8

A mercury manometer is used to measure the pressure in a pipe. If the height difference between the two columns is 20 cm, what is the pressure in the pipe?

Accepted Answer

2.72 kPa

Answer

1.68 kPa

Answer

3.36 kPa

Answer

4.04 kPa

Question 9

A ship floats in water because:

Accepted Answer

Its weight is less than the weight of the water it displaces

Answer

Of the air trapped inside the ship

Answer

Of the shape of the ship's hull

Answer

Of the surface tension of the water

Question 10

The metacenter of a floating object is the point through which the line of action of the buoyant force passes:

Accepted Answer

When the object is slightly tilted from its equilibrium position

Answer

When the object is completely submerged

Answer

When the object is sinking

Answer

When the object is at rest

Question 11

Which of the following statements about the center of gravity of a floating object is true?

Accepted Answer

It must be below the metacenter for stable equilibrium

Answer

It must be above the metacenter for stable equilibrium

Answer

It can be at any point relative to the metacenter for stable equilibrium

Answer

It has no effect on the stability of the object

Question 12

A submarine submerges by:

Accepted Answer

Taking in water into ballast tanks

Answer

Releasing air from ballast tanks

Answer

Increasing its speed

Answer

Decreasing its buoyancy

Question 13

The pressure inside a gas bubble submerged in a liquid is:

Accepted Answer

Greater than the hydrostatic pressure at the bubble's depth

Answer

Equal to the hydrostatic pressure at the bubble's depth

Answer

Less than the hydrostatic pressure at the bubble's depth

Answer

Zero

Question 14

Which of the following fluids is most likely to exhibit laminar flow?

Accepted Answer

Water at low velocities

Answer

Oil at high temperatures

Answer

Air at high pressure

Answer

Mercury at room temperature

Question 15

The Reynolds number is a dimensionless quantity used to characterize:

Accepted Answer

The type of flow (laminar or turbulent)

Answer

The pressure drop in a pipe

Answer

The velocity of a fluid

Answer

The viscosity of a fluid

Question 16

State Pascal's law in your own words.

Accepted Answer

Pressure applied to a fluid is transmitted equally and undiminished throughout the fluid.

Answer

Fluids exert a force on surfaces perpendicular to the surface.

Answer

The force exerted by a fluid on a surface is proportional to the area of the surface.

Answer

The pressure in a fluid increases with depth.

Question 17

Which instrument is commonly used to measure pressure in a fluid?

Accepted Answer

Manometer

Answer

Thermometer

Answer

Barometer

Answer

Anemometer

Question 18

Define fluid pressure.

Accepted Answer

The force exerted by a fluid on any surface in contact with it, perpendicular to the surface.

Answer

The force exerted by a fluid on a surface parallel to the surface.

Answer

The pressure at a specific point in a fluid.

Answer

The difference in pressure between two points in a fluid.

Question 19

Which of the following is NOT a type of hydrostatic pressure?

Accepted Answer

Dynamic pressure

Answer

Atmospheric pressure

Answer

Gauge pressure

Answer

Vacuum pressure

Question 20

Describe the purpose of a manometer.

Accepted Answer

To measure the difference in pressure between two points in a fluid.

Answer

To measure the absolute pressure of a fluid.

Answer

To measure the flow rate of a fluid.

Answer

To measure the density of a fluid.

Question 21

Which fundamental concept is NOT covered in fluid statics?

Accepted Answer

Viscosity

Answer

Pressure

Answer

Buoyancy

Answer

Stability of floating bodies

Question 22

Pascal's law states that:

Accepted Answer

Pressure applied to a confined fluid is transmitted equally in all directions

Answer

Buoyant force is equal to the weight of the fluid displaced

Answer

Center of buoyancy is located at the center of gravity of the submerged object

Answer

Stability of a floating body depends on its metacentric height

Question 23

The buoyant force acting on an object immersed in a fluid is:

Accepted Answer

Equal to the weight of the displaced fluid

Answer

Equal to the weight of the object

Answer

Equal to the density of the fluid multiplied by the volume of the object

Answer

Opposite to the weight of the object

Question 24

A floating object is stable when its:

Accepted Answer

Center of gravity is lower than its center of buoyancy

Answer

Center of gravity is higher than its center of buoyancy

Answer

Center of gravity is the same as its center of buoyancy

Answer

Center of gravity is to the side of its center of buoyancy

Question 25

The standard unit of pressure in the SI system is the:

Accepted Answer

Pascal

Answer

Newton-meter

Answer

Joule

Answer

Watt

Question 26

A fluid is considered incompressible if its:

Accepted Answer

Density remains constant under pressure changes

Answer

Density changes significantly with pressure

Answer

Volume changes significantly with pressure

Answer

Viscosity changes significantly with pressure

Question 27

Which statement correctly defines pressure?

Accepted Answer

A scalar quantity indicating force applied perpendicular to a surface per unit area

Answer

A vector quantity indicating force applied parallel to a surface per unit area

Answer

A measure of the change in volume of a fluid per unit force

Answer

A measure of the force exerted by a fluid on a submerged object

Question 28

A manometer containing mercury is used to measure the pressure of a gas. The difference in the mercury levels between the two arms is 20 centimeters. The pressure of the gas is:

Accepted Answer

5.32 kPa

Answer

2.66 kPa

Answer

10.64 kPa

Answer

21.28 kPa

Question 29

Buoyancy is a force that:

Accepted Answer

Acts upward on a submerged or floating object

Answer

Acts downward on a submerged or floating object

Answer

Is proportional to the mass of the object

Answer

Is proportional to the density of the object

Question 30

A boat with a weight of 1000 N floats on the surface of a lake. The buoyant force acting on the boat is:

Accepted Answer

1000 N

Answer

500 N

Answer

1500 N

Answer

2000 N