Mechanical Engineering MCQ Question Papers: DRDO, ISRO, Interview

Subject: Hydraulics and Pneumatics 6

**Part 6: List for questions and answers of Hydraulics and Pneumatics**

**Q1. How is strong magnetic field in a solenoid achieved?**

a) Strong magnetic field in a solenoid is achieved, if coil acts as conductor

b) Coil is surrounded by a iron frame

c) Iron core is placed at the centre of the coil

d) All the above

**Q2. What is the DC range of solenoids in pneumatic systems?**

a) 12 V and 24 V

b) 110 V and 220 V

c) Both a and b

d) None of the above

**Q3.An internal mouthpiece is said to be running free if the length of the mouthpiece is __________ the diameter of the orifice**

a) Less than twice

b) More than twice

c) Less than three times

d) More than three times

**Q4.The volume of a fluid __________ as the pressure increases**

a) Remains same

b) Decreases

c) Increases

d) Constant

**Q5.The pressure of the liquid flowing through the divergent portion of a venturimeter**

a) Remains constant

b) Increases

c) Decreases

d) Depends upon mass of liquid

**Q6.A jet of water discharging from a 40 mm diameter orifice has a diameter of 32 mm at its vena contracta. The coefficient of contraction is**

a) 0.46

b) 0.64

c) 0.78

d) 0.87

**Q7.Water is a __________ fluid**

a) Real

b) Ideal

c) Newtonian

d) Non-Newtonian

**Q8.Barometer is used to measure**

a) Velocity of liquid

b) Atmospheric pressure

c) Pressure in pipes and channels

d) Difference of pressure between two points in a pipe

**Q9.The dynamic viscosity of the liquid __________ with rise in temperature**

a) Remain unaffected

b) Increases

c) Constant

d) Decreases

**Q10.The mass of 2.5 m3 of a certain liquid is 2 tonnes. Its mass density is**

a) 200 kg/m^3

b) 400 kg/m^3

c) 600 kg/m^3

d) 800 kg/m^3

**Q11.When a vertical wall is subjected to pressures due to liquid on both sides, the resultant pressure is the __________ of the two pressures**

a) Sum

b) Difference

c) Arithmetic mean

d) Geometric mean

**Q12.When the Mach number is between __________ the flow is called super-sonic flow**

a) 1 and 2.5

b) 2.5 and 4

c) 4 and 6

d) 1 and 6

**Q13.The factional resistance of a pipe varies approximately with __________ of the liquid**

a) Pressure

b) Velocity

c) Square of velocity

d) Cube of velocity

**Q14.A manometer is used to measure**

a) Atmospheric pressure

b) Pressure in pipes and channels

c) Pressure in venturimeter

d) Difference of pressures between two points in a pipe

**Q15.The product of mass and acceleration of flowing liquid is called**

a) Inertia force

b) Viscous force

c) Gravity force

d) Pressure force

**Q16.A point, in a compressible flow where the velocity of fluid is zero, is called**

a) Critical point

b) Vena contracta

c) Stagnation point

d) None of these

**Q17.Falling drops of water become spheres due to the property of**

a) Surface tension of water

b) Compressibility of water

c) Capillarity of water

d) Viscosity of water

**Q18.The height of a water column equivalent to a pressure of 0.15 mpa is**

a) 15.3 m

b) 25.3 m

c) 35.3 m

d) 45.3 m

**Q19.The total energy of a liquid particle in motion is equal to**

a) Pressure energy + kinetic energy + potential energy

b) Pressure energy – (kinetic energy + potential energy)

c) Potential energy – (pressure energy + kinetic energy

d) Kinetic energy – (pressure energy + potential energy)

**Q20.In case of flow through parallel pipes**

a) The head loss for all the pipes is same

b) The total discharge is equal to the sum of discharges in the various pipes

c) The total head loss is the sum of head losses in the various pipes

d) Both (A) and (B)

**Part 6: List for questions and answers of Hydraulics and Pneumatics**

Q1. Answer: d

Q2. Answer: a

Q3. Answer: c

Q4. Answer: b

Q5. Answer: c

Q6. Answer: b

Q7. Answer: c

Q8. Answer: b

Q9. Answer: d

Q10. Answer: d

Q11. Answer: b

Q12. Answer: d

Q13. Answer: c

Q14. Answer: b

Q15. Answer: a

Q16. Answer: c

Q17. Answer: a

Q18. Answer: a

Q19. Answer: a

Q20. Answer: d