Fluid Mechanics (Part-3) (General Engineering) (SSC JE)

Total Questions: 50

11. Continuity equation for an incompressible fluid is [BPSC AE (GEN ENGG.)-03.12.2012 ]

Correct Answer: (b)
Solution:

Continuity equation for one-dimensional flow

Flow continuity, through a stream tube

12. Coefficient of discharge is equal to [BPSC AE (GEN. ENGG.)-29.03.2019 ]

Correct Answer: (a)
Solution:

13. The loss of head at entrance in a pipe is [BPSC AE (GEN. ENGG.)-29.03.2019 ]

Correct Answer: (b) 0.5v²/2g
Solution:

The major loss of head or energy is due to friction. The minor loss of head includes the following cases–

14. The kinematic viscosity of an oil (in stokes) whose specific gravity is 0.95 and viscosity 0.011 poise is [BPSC AE (GEN. ENGG.)-29.03.2019 ]

Correct Answer: (a) 0.0116
Solution:

15. Whenever a plate is held immersed at some angle with the direction of flow of the liquid, it is subjected to some pressure. The component of this pressure, at right angles to the direction of flow of the liquid is known as [BPSC AE (GEN. ENGG.)-29.03.2019 ]

Correct Answer: (a) lift
Solution:

Lift– Whenever a plate is held immersed at some angle with the direction of flow of the liquids. It is subjected to some pressure, which acts at right angles to the plate.

• The component of this pressure at right angle to the direction of flow of the liquid is known as lift. Thus the force lift,
Note–This creation of lift, on the bodies is used for propelling sea ships and for supporting the weight of the flying aeroplanes.

16. Which of the following identify the dimensionless quantities? [RRB JE (Muzaffarpur) 14.12.2014 ]

Correct Answer: (d) All of these
Solution:

Pressure coefficient, Froude number and Darcy Weisbach friction factor are dimensionless quantities.
Pressure Coefficient– It is the ratio of pressure force to inertia force. The pressure coefficient is important in most fluid flow applications.
Froude's Number– It is the ratio of inertia force to gravity force.

17. The General energy equation applies …… [RRB S.S.E (Bhopal) 21.12.2014 ]

Correct Answer: (a) To steady flow
Solution:

As per General energy equation it is assumed that the energy is conserved during flow and it can be interchange into kinetic energy, pressure energy or potential energy for steady and uniform flow. i.e. Bernoulli equation.

18. Stalagmometer is used to measure------. [RRB S.S.E (Bhopal) 21.12.2014 ]

Correct Answer: (b) surface tension
Solution:

Stalagmometer–A simple and normally manual instrument for measuring surface tension of liquids. Tensiometer is used to measure soil moisture/water tension.

19. When a liquid rotates at constant angular velocity about a vertical axis as a rigid body, the pressure intensity [BPSC AE (GEN. ENGG.) 16.09.2018 ]

Correct Answer: (d) varies as square of radial distance
Solution:


20. The no-slip boundary condition applied in a fluid [BPSC AE (GEN. ENGG.) 16.09.2018 ]

Correct Answer: (d) because the fluid is viscous
Solution:

Boundary condition for viscous flows is the no slip condition. If the boundary is rigid and fixed, the no slip condition states that the fluid velocity at the boundary is zero.
• No slip boundary condition related to zero fluid velocity relative to the solid at the fluid solid interface.
• No slip condition at rigid boundaries applicable to flow of all real fluids.