1. A reciprocating pump
A. requires priming
B. requires air vessel
C. requires high operating speeds
D. is used for viscous fluids only
Answer - Option B
Explanation -
A reciprocating pump is self priming. It operates at low speeds. It is not suitable for viscous liquids, paper pulp, molasses, etc.
2. Air vessel in a reciprocating pump is used to
A. obtain continuous supply of water at uniform rate
B. increase delivery
C. reduce suction head
D. remove any entrapped air from water
Answer - Option A
Explanation -
Air vessel smooth-ens water discharge which is otherwise pulsating. Air vessel may be fitted on suction side and/or delivery side.
3. A tapered draft tube as compared to a cylindrical draft tube
A. prevents hammer blow and surges
B. responds better to load functions
C. converts more of kinetic head into pressure head
D. prevents cavitation even under reduced discharges
Answer - Option C
Explanation -
A tapered draft tube is used for low specific speed vertical shaft turbines. Its maximum cone angle
is 8°. If angle is more than this, water does not touch the inner walls, causing vertices and loss of head. Maximum efficiency obtained in this tube is 9%. The tube must discharge sufficiently below the tail water level.
4. The specific speeds of radial vane pump, mixed flow pump and axial flow pump are [latex]{NS}_{1}[/latex], [latex]{NS}_{2}[/latex] and [latex]{NS}_{3}[/latex] respectively. Then
A. [latex]{NS}_{1} > {NS}_{2} >{NS}_{3}[/latex]
B. [latex]{NS}_{3} > {NS}_{2} >{NS}_{1}[/latex]
C. [latex]{NS}_{2} > {NS}_{3} >{NS}_{1}[/latex]
D. [latex]{NS}_{3} > {NS}_{1} >{NS}_{2}[/latex]
Answer - Option B
5. Centrifugal pumps operating in series will result in
A. higher discharge
B. reduced power consumption
C. higher head
D. low speed operation
Answer - Option C
Explanation -
Series operation is achieved by having one pump discharge into he suction of the next . This
arrangement is used primarily to increase the discharge head.
6.Jet pumps are often used in process industry for their
A. high efficiency
B. easy maintenance
C. large capacity
D. capacity to transport gases, liquids and mixtures of both
Answer - Option B, D
7.Spouting velocity is
A. ideal velocity of jet
B. 50% of ideal velocity of jet
C. actual velocity of jet
D. velocity of jet under some specified conditions
Answer - Option A
8. The comparison between pumps operating in series and in parallel is
A. Pumps operating in series boost the discharge, whereas pumps operating in parallel boost the head.
B. Pumps operating in parallel boost the discharge, whereas pumps operating in series
boost the head
C. In both cases there would be a boost in discharge only.
D. In both cases there would be a boost in head only.
Answer - Option B
9.A pelton turbine is considered suitable for which of the following head ?
A. 10 to 12 metres
B. 20 to 30 metres
C. 35 to 50 metres
D. 100 to 250 metres
Answer - Option D
Explanation -
By extrapolating Q vs H curve, the shut off head which is corresponding to Q = 0 is 35.5 m.
10.Material for water turbine should have
A. high creep resistance
B. high temperature resistance
C. high corrosion resistance
D. low ductility
Answer - Option C
11. The coefficient of discharge ( [latex]{C}_{D}[/latex]) of an orifice varies with
A. Reynolds number
B. Weber number
C. Froude number
D. Mach number
Answer - Option A
12. The shear stress distribution for a fluid flowing in between the parallel plates, both at rest, is
A. constant over the cross-section
B. maximum at the mid-plane and varies linearly with distance from mid-plane
C. zero at the mid-point and varies linearly with distance from mid-plane
D. zero at the plates and varies exponentially to mid-point
Answer - Option C
13. Friction drag is generally larger than the pressure drag in
A. flow past a sphere
B. flow past a cylinder
C. flow past an airfoil
D. flow past a thin sheet
Answer - Option B
14. Capillarity is due to
A. Cohension
B. Adhesion
C. Adhesion and cohesion
D. Gravity
Answer - Option C
15. Principle of similitude forms the basis of
A. comparing two identical equipment
B. designing models so that the result can be converted to prototypes
C. comparing similar ly between design and actual equipment
D. hydraulic design
Answer - Option B
16. If V is the mean velocity of flow, then according to Darcy-Weisbach equation for pipe flow, energy loss over a length of pipe is proportional
A. V
B. [latex]\frac{1}{V}[/latex]
C. [latex]{V}^{2}[/latex]
D. [latex]\sqrt{V} [/latex]
Answer - Option B
17. Head loss in turbulent flow in a pipe
A. varies directly as velocity
B. varies inversely as square of velocity
C. varies approximately as square of velocity
D. varies inversely as velocity.
Answer - Option D
18. The horizontal component of force on a curved surface is equal to the
A. product of pressure at its centroid and area
B. weight of liquid retained by the curved area
C. force on a vertical projection of the curved surface
D. weight of liquid vertically above the curved surface
Answer - Option C
19. Total pressure on the top of a closed cylindrical vessel of radius r filled with liquid is
proportional to
A. r
B. [latex]\frac{1}{r}[/latex]
C. [latex]\frac{1}{{r}^{2}}[/latex]
D. [latex]{r}^{2}[/latex]
Answer - Option D
20. The drag coefficient for laminar flow varies as (where Re = Reynolds number)
A. Re
B. [latex]{r}^{-1}[/latex]
C. [latex]{r}^{\frac{1}{2}}[/latex]
D. [latex]{r}^{- \frac{1}{2}}[/latex]
Answer - Option D