Explore topic-wise MCQs in Fluid Mechanics.

This section includes 185 Mcqs, each offering curated multiple-choice questions to sharpen your Fluid Mechanics knowledge and support exam preparation. Choose a topic below to get started.

151.

Enthalpy is calculated as the

A. Sum of internal energy and the product of pressure and volume of the system
B. Sum of internal energy and the product of pressure and density of the system
C. Difference between the internal energy and the product of pressure and density of the system
D. Difference between the internal energy and the product of pressure and volume of the system
Answer» B. Sum of internal energy and the product of pressure and density of the system
152.

Figure shows the P-V diagram of an ideal gas. The work done by the gas in the process ABCDA is:

A. 0.5PV
B. 2PV
C. 1.5PV
D. 4PV
Answer» D. 4PV
153.

In high-pressure compressor discharge pressure is

A. 1 to 5 kg/cm2
B. 10 to 15 kg/cm2
C. 8 to 10 kg/cm2
D. 5 to 8 kg/cm2
Answer» C. 8 to 10 kg/cm2
154.

In an isothermal process, the internal energy of an ideal gas

A. Always increases
B. Always decreases
C. Increases or decreases
D. Remains constant
Answer» E.
155.

A 10 kg solid at 373 K with a specific heat of 0.8 kJ/kg-K is immersed in 40 kg of 293 K liquid with a specific heat of 4.0 kJ/kg-K. The temperature after a long time, if the container is insulated -

A. 303 K
B. 301 K
C. 299 K
D. 297 K
Answer» E.
156.

A perfect gas is heated at constant pressure from 30°C till its volume become double. Then the final temperature is:

A. 120°C
B. 303°C
C. 60°C
D. 333°C
Answer» E.
157.

For isochoric processes, which of the following property remains constant?

A. Volume
B. Temperature
C. Pressure
D. Entropy
Answer» B. Temperature
158.

One mole of a monoatomic gas is taken through a cycle ABCDA as shown in the P-V diagram. Column II give the characteristics involved in the cycle. Match the process A → B with the processes given in Column II.Column – IProcess A → BProcess B → CProcess C → DProcess D → AColumn – IIp) Internal energy decreasesq) Internal energy increases.r) Heat is losts) Heat is gainedt) Work is done on the gasProcess A → B signifies

A. p, q
B. r, s
C. p, r, t
D. q, t
Answer» D. q, t
159.

During throttling, which thermodynamic property does not change?

A. Entropy
B. Enthalpy
C. Internal energy
D. Pressure
Answer» C. Internal energy
160.

A piston of 0.1 m diameter expands over a stroke of 0.2 m under constant gas pressure of 2 × 105 N/m2. The work done by the piston is:

A. 31.4 J
B. 42 J
C. 314.2 J
D. 21.5 W
Answer» D. 21.5 W
161.

In an isentropic flow through a nozzle, air flows at the rate of 600 kg/hr. At inlet to nozzle, the pressure is 2 MPa and the temperature is 127°C. The exit pressure is of 0.5 MPa. If the initial velocity of air is 300 m/s, the exit velocity will be

A. 867 m/s
B. 776 m/s
C. 685 m/s
D. 594 m/s
Answer» E.
162.

A re-entry module flies with Mach 10 at an ambient temperature of -27°C with CP = 840 J/kg-K, gas constant R = 140 J/kg-K. What is the stagnation temperature at the tip of the nose of the re-entry module?

A. -23°C
B. 1377°C
C. 2477°C
D. -253°C
Answer» D. -253°C
163.

A system is said to be in thermodynamic equilibrium if the system is in:

A. chemical equilibrium
B. thermal, chemical and mechanical equilibrium
C. thermal equilibrium
D. mechanical equilibrium
Answer» C. thermal equilibrium
164.

During a process on the closed system, its internal energy increases by twice the units than the heat added to it. It is possible due to

A. radiation of heat from surroundings
B. lowering of the temperature
C. increasing of the temperature
D. performing of shaft work on the system
Answer» E.
165.

A steel ball of mass 1 kg and specific heat 0.4 kJ/kgK is at a temperature of 60°C. It is dropped into 1 kg water at 20°C. The final steady state temperature of water is

A. 23.5°C
B. 30°C
C. 35°C
D. 40°C
Answer» B. 30°C
166.

If the specific heats of the working fluid are constant and the value of specific heat ratio γ is 1.4, the thermal efficiency (%) of the cycle is

A. 21
B. 40.9
C. 42.6
D. 59.7
Answer» B. 40.9
167.

A thermodynamic process during which the volume of the closed system in consideration remains constant is called _________.

A. Isochoric process
B. Isobaric process
C. Adiabatic process
D. Isothermal process
Answer» B. Isobaric process
168.

Properties of substances like pressure, temperature and density, in thermodynamic co-ordinates are _____.

A. Path functions
B. Point functions
C. Cyclic functions
D. Real functions
Answer» C. Cyclic functions
169.

Identify the complete and correct statement of the first law of thermodynamics

A. During a process, extracting work without supplying heat, while sacrificing the energy of the system.
B. Difference between the heat and work interactions during a process, which is property of the system.
C. When a closed system executes a complete cycle, the sum of heat interactions is equal to the sum of work interactions.
D. When a system undergoes a cycle, the integral of heat is equal to the integral of work.
Answer» D. When a system undergoes a cycle, the integral of heat is equal to the integral of work.
170.

In a closed system, volume changes from 1 m3 to 2 m3 and heat addition is 2000 kJ. The change in internal energy given the pressure volume relation as p = 1000 V kPa, Where V is volume in m3

A. 500 kJ
B. 1500 kJ
C. 3500 kJ
D. 4500 kJ
Answer» B. 1500 kJ
171.

A system undergoes a change of state during which 100 kJ of heat is transferred to it and it does 50 kJ of work. The system is brought back to its original state through a process during which 120 kJ of heat is transferred to it. The work done by the system in kJ is

A. 50
B. 70
C. 170
D. 200
Answer» D. 200
172.

__________ is NOT a property of a system.

A. Specific volume
B. Heat
C. Temperature
D. Pressure
Answer» C. Temperature
173.

If mass flow rate of steam through the turbine is 20kg/s, the power output of the turbine (in MW) is

A. 12.157
B. 12.941
C. 168.001
D. 168.785
Answer» B. 12.941
174.

Ice kept in a well-insulated thermo flask is an example of which system?

A. Closed system
B. Isolated system
C. Open system
D. Non-flow adiabatic system
Answer» C. Open system
175.

1 kg liquid (specific heat = 3.0 kJ/kg-K) is stirred in closed chamber and its temperature is raised by 10°C. Heat loss to the surrounding is 3.0 kJ. The work done on the water during the process will be:

A. 30 kJ
B. 27 kJ
C. 33 kJ
D. 36 kJ
Answer» D. 36 kJ
176.

WHICH_AMONG_THIS_IS_NOT_AN_EXOTHERMIC_REACTION??$

A. Combustion reaction
B. Neutralization reaction
C. Thermite reaction
D. Evaporating liquid water
Answer» E.
177.

What_reaction_takes_place_during_photosynthesis?$

A. Exothermic reaction
B. Endothermic reaction
C. Redox reaction
D. Combustion reaction
Answer» C. Redox reaction
178.

SI unit of enthalpy is______?

A. Joule/kgK
B. Joule/K
C. Joule/kg
D. K/kg
Answer» D. K/kg
179.

What is the equation of entropy?

A. Ratio of reversible transfer of heat to absolute temperature
B. Ratio of absolute temperature to reversible heat transfer
C. Ratio of adiabatic heat to macroscopic variables
D. Ratio of macroscopic variables to adiabatic heat
Answer» B. Ratio of absolute temperature to reversible heat transfer
180.

Entropy occurs due to _______

A. Change in macroscopic variables
B. Volumetric changes only
C. Mass changes only
D. Temperature only
Answer» B. Volumetric changes only
181.

An increase in enthalpy leads to an increase in __________

A. Increase in pressure
B. Increase in volume
C. Increase in internal energy
D. Increase in mass
Answer» D. Increase in mass
182.

The equation for the average kinetic energy is_________

A. 0.5 KT
B. 1.5 KT
C. 2.5 KT
D. 3.5 KT
Answer» C. 2.5 KT
183.

During a fluid flow, the temperature is developed due to________

A. Increase in density
B. Change in pressure
C. Translational Kinetic Energy
D. Fluid level
Answer» D. Fluid level
184.

Equation of the first law of thermodynamics is ________

A. Internal Energy= Heat added into work done
B. Internal Energy= Heat rejected into work done
C. Internal Energy= Heat added divided by work done
D. Internal Energy=Heat added plus work done
Answer» E.
185.

First law of thermodynamics deals with _______

A. Conservation of mass
B. Conservation of momentum
C. Conservation of energy
D. Conservation of pressure
Answer» D. Conservation of pressure