Maharashtra State Board of Technical Education 2012-4th Sem Diploma Mechanical Engineering for Mechanical EngineeringSubject FMM(12093) - Question Paper
Monday, 06 May 2013 04:20Web
12093
11122
3 Hours / 100 marks
Instructions:
1. All ques. are compulsory.
2. presume suitable data, if necessary.
2. Figures to the right indicate full marks.
3. Use non programmable Electronic pocket calculator is permissible.
4. MObile phones, pager and other electronic communication devices are not permissible in
exam hall.
Q.1 a) Attempt any 6 of the subsequent [Marks 12]
a) describe
a) Specific quantity
b) Compressibility
b) Differentiate ranging from absolute pressure and gauge pressure.
c) describe
a) Stream-line flow
b) uniform flow
d) State laws of fluid friction for steady streamline flow.
e) describe the term Impact of jet.
f) Compare Impulse Turbine and Reaction Turbine.
g) Why priming is necessary for centrifugal pump?
h) What is 'negative slip' in reciprocating pump?
b) Attempt any 2 of the subsequent [Marks 8]
i) What is NPSH related to centrifugal pump?
ii) A circular plate 1.2 m in diameter is placed vertically in water so that centre of the plate is
two m beneath the free surface. Determine the depth of centre of pressure.
iii) discuss
a) surface tension
b) vapour pressure.
Q.2 Attempt any 4 of the subsequent [Marks 16]
a) discuss construction and working of submersible pump with sketch.
b) A jet of water 50 mm diameter is discharging under a constant head of 70 meters. obtain the force
exerted by the jet on a fixed plate. Take coefficient of velocity as 0.9
c) A pipe of 60 meters long and 150 mm in diameter is connected to a water tank at 1 end and
flows freely into the atmosphere at the other end. The height of water level in the tank is 2.6
meters above the centre of the pipe. The pipe is horizontal and f=0.01. Determine the discharge
through the pipe in litres/s, if all the minor losses are to be considered.
d) Draw a neat sketch of Impact of jet on inclined fixed plate and write formula for different forces
exerted on it.
e) At a certain point in castor oil the shear stress is 0.216 N/m2 and the velocity
gradient 0.216 s-1>/sup>. If mass density of castor oil is 959.42 Kg/m3, obtain
kinematic viscosity.
f) discuss working principle of Differential manometer with neat sketch.
Q.3 Attempt any 4 of the subsequent [Marks 16]
a) Sketch and discuss Bourdon pressure gauge.
b) A venturimeter has an area ratio nine to 1, the larger diameter being 300 mm. During the flow, the
recorded pressure head in the large part is 6.5 meters and that at the throat 4.25 meters. If
the meter coefficient (C) =0.99, calculate the discharge through the meter.
c) State necessity of draft tube in turbines. discuss any 1 with sketch.
d) A jet of water 75 mm in diameter having velocity of 20 m/s. Strikes of the flat plates organizes
around the periphery of a wheel such that every plate appears successively before the jet. If the
plates are moving at a velocity of five m/s, computer the force exerted by the jet on the plate,
the work done per 2nd on the plate and the efficiency of the jet.
e) discuss Hydraulic gradient line and total energy line related to flow through pipes.
f) describe
a) pressure head
b) pressure intensity
c) absolute vacuum
d) atmospheric pressure.
Q.4 Attempt any 2 of the subsequent [Marks 16]
a) A pelton wheel turbine is to operate under a head of 25 m at 200 r.p.m. If the discharge is nine
m3/s and turbine efficiency is 90%, compute power generated by the turbine,
specific speed of the turbine and performance of turbine under a head of 20 m. Also state the
kind of turbine.
b) discuss construction and working of double acting reciprocating pump with neat sketch.
c) Write short note on
1) Darcy's formula
2) Hydraulic power transmission through pipes.
Q.5 Attempt any 2 of the subsequent [Marks 16]
a) discuss concepts of
1) Total pressure
2) Centre of pressure
3) Rotational flow
4) Unsteady flow
b) What is 'Vena-contracta' related to Orifice meter? A 60 mm diameter Orifice is discharging water
under a head of nine meters. compute the true discharge through the Orfice in litres per 2nd
and true velocity of the jet in m/s at vena contracta, if Cd=0.625 and Cv=0.98.
c) Draw a layout of Hydro-electric power plant and write function of its major components.
Q.6 Attempt any 2 of the subsequent [Marks 16]
a) What is pitot tube? discuss with sketch.
b) Draw indicator diagram with effect of 'acceleration head' and 'friction head' for single acting
reciprocating pump. Why air vessel is needed for reciprocating pump?
c) A centrifugal pump delivers 30 litres of water per 2nd to a height of 18 meters through a
pipe 90 m long and 100 mm diameter. If overall efficiency of the pump is 75%. obtain the power
needed to drive the pump. Take f=0.012.
| Earning: Approval pending. |
