Physics

Fluid Mechanics

673 Questions

Fluid mechanics is a core physics topic that evaluates the principles of liquid pressure, buoyancy, density, and viscosity through complex numerical problems. The questions require calculating the volume of submerged objects, understanding hydraulic jumps, and applying fundamental fluid statics principles. It is a highly scoring subject for candidates preparing for technical and engineering competitive exams.

Liquid pressure and depthBuoyancy and densityVolume expansionHydraulic jump calculationsSurface tension mechanics

Fluid Mechanics Questions

Multiple choice physics pressure pressure in fluids pressure in liquids introduction to pressure

The Pressure at any point in the liquid is proportional to :

  1. The density of liquid.

  2. The depth of point below the surface.

  3. The acceleration due to gravity.

  4. All the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pressure at any point in the liquid $(P)=hdg$
i.e., $P\alpha h$
(depth of point below the surface)
$\alpha d$ (density of liquid)
$\alpha g$ (acceleration due to gravity)

Multiple choice physics pressure pressure in fluids pressure in liquids introduction to pressure

Liquid pressure at a point in a liquid does not depend on the :

  1. Density of liquid

  2. Shape of the vessel in which the liquid is kept

  3. Depth of the point from the surface

  4. Acceleration due to gravity
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

pressure in a fluid = $\rho gh $ 

so clearly it is independent of the shape of the vessel in which the liquid is kept .
hence option (B) is correct .

Multiple choice physics fluids pressure in fluids pressure in liquids introduction to pressure

Pressure at a point inside the liquid does not depend upon :

  1. The depth of the point below the surface of the liquid.

  2. The nature of the liquid.

  3. The acceleration due to gravity at that point.

  4. The shape of the container.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pressure at a point inside the liquid $(P)=hdg$
Hence, it depends on the depth of the point below the surface of the liquid the acceleration due to gravity at that point and on the nature of the liquid but not on the shape of the containing liquid.

Multiple choice biology simple nutrients into cells blood and its components components of blood composition of blood

Plasma has water to the extent of _____________.

  1. $80\%$
  2. $60\%$
  3. $70\%$
  4. $90\%$ or more
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Plasma, which is 92 percent water, constitutes 55 percent of blood volume. Plasma contains albumin (the chief protein constituent), fibrinogen (responsible, in part, for the clotting of blood), and globulins (including antibodies).


So, the correct answer is '90%'.

Multiple choice

The pressure exerted by a fluid at a given point is known as:

  1. Atmospheric pressure

  2. Gauge pressure

  3. Absolute pressure

  4. Hydrostatic pressure
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hydrostatic pressure is the pressure exerted by a fluid at a given point due to the weight of the fluid above that point.

Multiple choice

The Bernoulli equation is used to describe:

  1. Energy conservation in a fluid flow.

  2. Momentum conservation in a fluid flow.

  3. Mass conservation in a fluid flow.

  4. Heat transfer in a fluid flow.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Bernoulli equation is a fundamental equation in fluid mechanics that describes the conservation of energy in a fluid flow.

Multiple choice

The Navier-Stokes equations are a system of partial differential equations that govern:

  1. Fluid flow.

  2. Heat transfer.

  3. Mass transfer.

  4. Chemical reactions.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Navier-Stokes equations are a system of partial differential equations that govern the motion of viscous fluids.

Multiple choice

The principle of buoyancy states that:

  1. An object immersed in a fluid experiences an upward force equal to the weight of the fluid displaced by the object.

  2. An object immersed in a fluid experiences a downward force equal to the weight of the fluid displaced by the object.

  3. An object immersed in a fluid experiences no force.

  4. An object immersed in a fluid experiences a force equal to the difference between the weight of the object and the weight of the fluid displaced by the object.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The principle of buoyancy states that an object immersed in a fluid experiences an upward force equal to the weight of the fluid displaced by the object.

Multiple choice

The equation that describes the conservation of energy for a fluid is:

  1. Continuity Equation

  2. Navier-Stokes Equations

  3. Euler Equations

  4. Bernoulli's Equation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Bernoulli's equation is a statement of the conservation of energy for an incompressible fluid.

Multiple choice

Which of the following is a unit of pressure?

  1. Pascal

  2. Atmosphere

  3. Bar

  4. Pound per square inch
Reveal answer Fill a bubble to check yourself
Correct answer
Explanation

The SI unit of pressure is the pascal, but atmospheres, bars, and pounds per square inch are also commonly used units of pressure.

Multiple choice

What is the term used to describe the phenomenon where a propeller loses efficiency due to cavitation?

  1. Propeller slip

  2. Propeller cavitation

  3. Propeller vibration

  4. Propeller noise
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Propeller cavitation occurs when the pressure around the propeller blades drops below the vapor pressure of the water, causing the formation of vapor bubbles that can reduce propeller efficiency.

Multiple choice

What is the term used to describe the ratio of the actual propeller speed to the theoretical propeller speed?

  1. Propeller slip

  2. Propeller cavitation

  3. Propeller vibration

  4. Propeller noise
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Propeller slip is the difference between the actual propeller speed and the theoretical propeller speed, which is determined based on the vessel's speed and the propeller's pitch.

Multiple choice

Which of the following is an example of a bifurcation?

  1. The transition from laminar to turbulent flow in a fluid.

  2. The sudden change in the behavior of a pendulum when it is pushed too far.

  3. The abrupt change in the climate of a region due to a small change in temperature.

  4. All of the above.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Bifurcations can occur in a wide variety of physical, biological, and social systems. Some common examples include the transition from laminar to turbulent flow in a fluid, the sudden change in the behavior of a pendulum when it is pushed too far, and the abrupt change in the climate of a region due to a small change in temperature.