# Hydraulic Machines-Fluid Machineries – Set 03

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## Q1. High specific speed of turbine implies it is

(A) Propeller turbine
(B) Francis turbine
(C) Impulse turbine
(D) None of the above

## Q3. The efficiency of a Pelton wheel working under constant head __ with the increase in power.

(A) Remain same
(B) Increases
(C) Decreases
(D) None of these

## Q4. Which type of the pump is different from others in the same group?

(A) Screw pump
(B) Gear pump
(C) Cam and piston pump
(D) Plunger pump

## Q5. If V1 and V2 are the velocities of water at inlet and outlet of the draft tube respectively, then the efficiency of a draft tube is

(A) (V­1 – V2) / V1
(B) (V­1² – V2²) / V1²
(C) V1 / (V1 – V2)
(D) V1² / (V1² – V2²)

Answer: (B) (V­1² – V2²) / V1²

## Q6. High specific speed of a pump implies it is

(A) Centrifugal pump
(B) Mixed flow pump
(C) Axial flow pump
(D) Any one of the above

## Q7. The impeller of a centrifugal pump may have

(A) Volute casing
(B) Volute casing with guide blades
(C) Vortex casing
(D) Any one of these

Answer: (D) Any one of these

## Q8. The efficiency of a hydraulic press is given by (where W = Weight lifted by ram, P = Force applied on plunger, A = Area of ram, and a = Area of plunger)

(A) (W/p) × (A/a)
(B) (p/W) × (a/A)
(C) (W/p) × (a/A)
(D) (p/W) × (A/a)

## Q9. Medium specific speed of a pump implies it is

(A) Centrifugal pump
(B) Mixed flow pump
(C) Axial flow pump
(D) Any one of the above

## Q10. In a centrifugal pump, the liquid enters the pump

(A) At the top
(B) At the bottom
(C) At the canter
(D) From sides

## Q11. According to fan laws, for fans having constant wheel diameter, the air or gas capacity varies

(A) Directly as fan speed
(B) Square of fan speed
(C) Cube of fan speed
(D) Square root of fan speed

Answer: (A) Directly as fan speed

## Q12. The angle of taper on draft tube is

(A) Greater than 15°
(B) Greater than 8°
(C) Greater than 5°
(D) Less than 8°

## Q13. In a reciprocating pump, air vessels are used to

(A) Smoothen the flow

## Q14. If a pump is handling water and is discharging a certain flow Q at a constant total dynamic head requiring a definite B.H.P., the same pump when handling a liquid of specific gravity 0.75 and viscosity nearly same as of water would discharge

(A) Same quantity of liquid
(B) 0.75 Q
(C) Q/0.75
(D) 1.5 Q

Answer: (A) Same quantity of liquid

## Q15. The discharge through a reaction turbine __ with the increase in unit speed.

(A) Decreases
(B) Increases
(C) Remain same
(D) None of these

(A) 24.8 r.p.m.
(B) 48.2 r.p.m
(C) 82.4 r.p.m.
(D) 248 r.p.m

## Q17. A Pelton wheel is

(A) Tangential flow impulse turbine
(B) Inward flow impulse turbine
(C) Outward flow impulse turbine
(D) Inward flow reaction turbine

Answer: (A) Tangential flow impulse turbine

## Q18. The type of centrifugal pump preferred for a specific speed of 20 r.p.m. is

(A) Slow speed pump with radial flow at outlet
(B) Medium speed pump with radial flow at outlet
(C) High speed pump with radial flow at outlet
(D) High speed pump with axial flow at outlet

## Q19. The working of which of the following hydraulic units is based on Pascal’s law?

(A) Air lift pump
(B) Jet pump
(C) Hydraulic coupling
(D) Hydraulic press