# Practice Test: Question Set - 31

**1. The pressure head of a flow meter remains constant for**

- (A) Venturimeter

- (B) Orificemeter

- (C) Rotameter

- (D) Pitot tube

**2. Hydraulic mean depth (**

*D*) for a circular pipe of diameter_{m}*'D'*flowing full is 0.25*D*. For a circular channel, at*D*= 0.3_{m}*D*, gives the condition for the maximum- (A) Flow rate

- (B) Mean velocity

- (C) Both 'a' & 'b'

- (D) Neither 'a' nor 'b'

**3. Which of the following quantities are computed by using the hydraulic radius for non-circular ducts?**

- (A) Velocity and relative roughness

- (B) Head loss and velocity

- (C) Reynold number, relative roughness and head loss

- (D) Reynolds number and friction factor

**4. A 0.5 m high bed made up of a 1 mm dia glass sphere (density 2500 kg/m**

^{3}) is to be fluidized by water (density 1000 kg/m^{3}). If at the point of incipient fluidization, the bed voidage is 40%, the pressure drop across the bed is- (A) 4.4 KPa

- (B) 2.94 KPa

- (C) 3.7 KPa

- (D) None of these

**5. A pressure head of 320 metres of water in meters of CCl**

_{4}(sp.gr = 1.6) will be- (A) 100

- (B) 200

- (C) 320

- (D) 160

**6. Which of the following denotes the effect of compressibility in fluid flow?**

- (A) Weber number

- (B) Mach number

- (C) Euler number

- (D) Reynolds number

**7. For pipe flows, head is proportional to __________ at constant capacity(where,**

*D*= pipe diameter).- (A) 1/

*D*

- (B) 1/

*D*

^{2}

- (C) 1/

*D*

^{5}

- (D)

*D*

^{2}

**8. Reynolds number for water flow through a tube of I.D. 5 cm is 1500. If a liquid of 5 centipoise viscosity and 0.8 specific gravity flows in the same pipe at the same velocity, then the pressure drop will**

- (A) Increase

- (B) Decrease

- (C) Remain same

- (D) Data insufficient to predict pressure drop

**9. A perfect gas**

- (A) Does not satisfy

*PV*=

*nRT*

- (B) Is incompressible and has zero viscosity

- (C) Has constant specific heat

- (D) Can’t develop shear stresses

**10. The ratio of the depth of flow to the hydraulic radius for the most economical trapezoidal section, in open channel flow is**

- (A) 0.5

- (B) 1

- (C) 1.5

- (D) 2

**11. Check in a centrifugal pump is**

- (A) Provided in the discharge line

- (B) Generally a globe valve

- (C) Provided to prevent liquid from backing up through the pump when the
pump is turned off or accidently stops running

- (D) All (a), (b) and (c)

**12. Which of the following equations as suggested by Colebrook and White gives the increase in roughness of a new surface (ε**

_{0}) with age/time (*t*) (where, ε = roughness of the surface after time '*t*'. α = a co-efficient to be experimentally determined)?- (A) ε = ε

_{0}+ α.

*t*

- (B) ε = ε

_{0}+ α.

*t*

^{2}- (C) ε = ε

_{0}+ α.

*t*

^{3}- (D) ε = ε

_{0}+ α.

*t*

^{4}**13. Reciprocating pumps are not able to compete with the centrifugal pump for industrial use, mainly because these pumps have**

- (A) Very low speeds

- (B) Smaller discharge

- (C) Higher capital &maintenance cost

- (D) High vibrations

**14. __________ pumps are axial flow pumps.**

- (A) Turbine

- (B) Propeller

- (C) Diffuser

- (D) None of these

**15. In an incompressible fluid, the density is**

- (A) Greatly affected by moderate changes in pressure

- (B) Greatly affected only by moderate changes in temperature

- (C) Not affected with moderate change in temperature
& pressure

- (D) Sensible to changes in both temperature & pressure

**View All Answers**

**Next Tests:**