CS/B.TECH (ME/PWE/OLD)/SEM-4/ME-401/2013
2013
FLUID MACHINERY
Time Allotted : 3 Hours Full Marks : 70
The figures in the margin indicate full marks.
Candidates are required to give their answers in their own words
as far as practicable.
GROUP – A
( Multiple Choice Type Questions )
1. Choose the correct alternatives for the following :
10x1 = 10
i) By stock free entry it is meant
a) that the flow should enter the runner smoothly
b) that the relative velocity vector should have the
same direction as that of the tangent at the inlet
tip of the balde
c) that the absolute velocity vector should be
tangential to the inlet tip of the blade
d) that the velocity of flow should be natural.
ii) Turbines give best performance ( i.e. work at peak
efficiency ) when they are operated at full or designed
load. The performance of many turbines deteriorates
considerably at part loads. Which of the following
turbines is best suited for operations at part loads ?
a) Pelton turbine b) Francis turbibe
c) Kaplan turbine d) Propeller turbine.
iii) The net or effective head at the turbine is
a) the sum of gross head plus head loss in the
penstock
b) the sum of gross head plus head loss in the
penstock and the velocity head at the turbine exit
c) the difference between gross head minus head
loss in penstock
d) the difference between gross head minus head
loss in penstock and the velocity head at the
turbine exit.
iv) The power obtainable from an impulse turbine is
proportional to the number of nozzles used. A pelton
turbine with six nozzles has a specific speed of 8·1.
The specific speed per nozzle is
a) 1·35 b) 3·3
c) 2 d) 8·1.