Unit-1 to 6

GURGAON INSTITUTE OF TECHNOLOGY & MANAGEMENT
Sem:1st
Session: 2008-09
Department of Mechanical Engineering
Course Name: Elements of Mechanical Engineering
Course Code: ME-101-E
Assignment no. 1
Faculty: R K Gupta
Professor

Q1(a). Define the following terms: (i) Dryness fraction (ii) Wetness fraction (iii) Vaporization, Evaporation & Boiling.
(b). Discuss the constructional & operational details of Cochran Boiler. (Dec.2007)

Q2(a). Enumerate the which should be considered while selecting a boiler.
(b). Give comparisons between Fire tube boiler and water tube boiler.
( C). 1 Kg of steam undergoes of reversible isothermal process from 20 bar and 250 °C to a pressure of 30 bar. Calculate the heat flow, stating whether it is supplied or rejected and sketch the process on a T-S diagram. (May 2007)

Q3 (a). What is the function of a safety valve? State the minimum number of safety valves to be used on a boiler.
(b). Write a short note on Moilier chart.
( C) A tank of capacity 0.5m3 is connected to a steam pipe through a valve which carries steam at 14 bar and 300°C. The tank initially contains steam at 3.5 bar and saturated condition. The valve in the line connecting the tank is opened and the steam is allowed to pass into the tank until the pressure in the tank becomes 14 bar. (Dec. 2006)

Q4(a).With the help of neat sketch explain the working of Babcock and Wilcox boiler.
(b) Repeat Q.2( C) ( May 2006)

Q5(a). Define a boiler. Can a boiler work without mounting? How do accessories differ from mounting?
(b) With the help of neat sketch, explain the working of a Feed-check valve.
(c ) 0.05 kg of steam is heated at a constant pressure of 2 bar until the volume occupied is 0.0658 m3. Calculate the heat supplied and work done. (Dec. 2005)

Q6.(a). A sample of steam from a boiler at 3 Mpa is put through a throttling calorimeter in which the pressure and temperature are found to be 0.1 Mpa, 120°C. Find the quality of sample taken from the boiler.
(b) Sketch and describe a cochran vertical boiler. What are its special features? (May 2005)

Q7(a). What is quality of steam? Describe the throttling calorimeter method of measurement of quality.
(b). Reapeat Q 4(a). (Dec. 2004)

Q8(a). What do you understand by the degree of superheat and the degree of subcooling?
(b). What is quality of steam? Repeat Q. 6(a) (May 2004)

Q9(a). Differentiate between saturated liquid and saturated vapour.
(b). Steam flows in a pipe-line at 1.5 MPa. After expanding to 0.1 MPa in a throttling calorimeter, the temperature is found to be 120°C. Find the quality of steam in the pipe-line. What is the maximum moisture at 1.5 MPa that can be determined with this set up if at least 5°C of superheat is required after throttling for accurate reading? (Dec. 2003)

Q10(a) Difference between water tube boiler & Fire tube boiler.
(b) What do you mean by boiler mounting & accessories? Discuss any five accessories in details with neat sketch.
[May 2008]




GURGAON INSTITUTE OF TECHNOLOGY & MANAGEMENT, GURGAON
Semester: I Sem
Session: 2008-09
Department of Mechanical Engineering
Course Name: Elements of Mechanical Engineering
Course Code: ME-101-E
Assignment No.2
Faculty: R K Gupta
Professor

Q1(a) Difference between Impulse and Reaction Turbines.
(b) Discuss about the compounding of Impulse Turbine with neat sketches. [Dec. 2007]

Q2(a) Explain with the help of neat sketch a single-stage impulse turbine. Also explain the pressure and velocity
variation along the axial direction.
(b) Explain the effects of air leakage in a condenser?
(c) What are the sources of air in the condenser? [May. 2007]

Q3(a) Define a steam condenser and state its objects.
(b) Explain with neat sketch the following condenser:
(i) Down flow type
(ii) Regenerative type
(iii) Evaporative type
( c) What methods are used in reducing the speed of the turbine rotor? Explain with the help of neat sketches.
(Dec. 2006)
Q4(a) Define a steam turbine and state its fields of application. How are the steam turbines classified?
(b) Classify the surface condenser and explain with neat sketches the following:
(i) Regenerative type
(ii) Evaporative type (May 2006)

Q5(a) Explain with the help of neat sketch a single stage impulse turbine. Also explain the pressure and velocity
variation along the axial direction.
(b) How will you classify condensers? In what respects a jet condenser differs from a surface condenser?
[Dec 2005]
Q6(a) Explain with the help of neat sketch a single stage impulse turbine. Also explain the pressure and velocity
variation along the axial direction.
(b) What purpose is served by a cooling tower in a steam power plant? Name the different types and gives a
brief description of each of them. [May 2005]

Q7(a) Discuss between operating features of an impulse and reaction steam turbines.
(b) Discuss the advantage of incorporating a condenser in a steam power plant. Describe with sketch the
Construction and working of a surface condenser. [Dec 2004]

Q8 What do you understand by compounding of steam turbines? Explain the terms pressure compounding and
Velocity compounding. [May 2004] &[Dec 2003]

Q9. Define following terms: Condenser efficiency, Vacuum efficiency.
Q10(a) Difference between jet condensers & surface condensers.
(b) What do you mean by cooling towers & cooling ponds? Classify various types of cooling towers with
neat sketch. [ May 2008]





GURGAON INSTITUTE OF TECHNOLOGY & MANAGEMENT, GURGAON
Semester: I Sem
Session: 2008-09
Department of Mechanical Engineering
Course Name: Elements of Mechanical Engineering
Course Code: ME-101-E
Assignment No.3
Faculty: R K Gupta
Professor

Q1(a) What do you mean by the thermal efficiency. Derive an expression for thermal efficiency for an otto cycle.
(b) In an air standard Diesel cycle with compression ratio 14, the conditions of air at the start of compression
stroke are 1 bar and 300 K. After addition of heat at constant pressure, the temperature rises to 2775 K.
Determine the thermal efficiency of the cycle, net work done per kg of air and mean effective pressure.
[Dec.2007]

Q2(a) Describe with a suitable sketch the two-stroke cycle spark ignition engine.
(b) Enumerate the various uses of Gas turbines.
(c) State the merits of gas turbine over IC engines and steam turbines. [May. 2007]

Q3(a) Compare the relative advantage and disadvantages of four-stroke and two-stroke cycle engines.
(b) Derive expression of efficiency for Diesel cycle. [Dec. 2006]

Q4(a) Explain with suitable sketches the working of a four-stroke Otto engine.
(b) Explain the following cycles on P-V and T-S chart:
(i) Otto Cycle or Constant volume cycle (ii) Diesel Cycle or Constant pressure cycle
(iii) Dual (Mixed or composite) Cycle [May. 2006]

Q5(a) In what respect four-stroke compression ignition engine differs from four- stroke spark ignition engine?
(b) Describe with neat sketch the working of a simple constant pressure open cycle gas turbine. [Dec. 2005]

Q6(a) What are the basic components of a gas turbine plant? Discuss the air standard cycle for such a plant.
(b) Explain the construction, working and applications of a two stroke C.I. engine. [May .2005]

Q7(a) Compare Otto,Diesel and Dual cycles on the basis of: (i) same compression ratio and heat rejection
(ii) same maximum pressure and temperature and same heat rejection. Explain with p-v and T-s diagram.
(b) Explain the construction, working and applications of a two stroke S.I. engine. [Dec.2004]

Q8 (a) Same as Q7(b)
(b) For the same compression ratio and heat rejection which cycle is most efficient Otto,Diesel and Dual
cycles? Explain with p-v and T-s diagram. [May. 2004]

Q9(a) are the basic components of a gas turbine plant? What is the air standard cycle of such a plant?What are
the process it consist of?
(b) Repeat Q 6(b) [Dec. 2003]

Q10(a) Comparison of Otto, Diesel and Dual Cycles.
(b) Difference between two stroke & four stroke engines. [May 2008]




GURGAON INSTITUTE OF TECHNOLOGY & MANAGEMENT, GURGAON
Semester: I Sem
Session: 2008-09
Department of Mechanical Engineering
Course Name: Elements of Mechanical Engineering
Course Code: ME-101-E
Assignment No.4
Faculty: R K Gupta
Professor

Q1.(a) Describe with neat sketches the construction and working of a Kaplan turbine. Why is a draft tube in a
Reaction turbine?
(b) What is priming in centrifugal pumps? Why is it necessary? [Dec. 2003]

Q2 (a) Describe with neat sketches, the construction and working of a Francis turbine. Why is the draft tube used
in such turbine?
(b) What is centrifugal pump? Different pump? Differentiate between the volute casing and vortex casing for
the centrifugal pump. [May 2004]

Q3(a) Draw a neat diagram of the layout of a Kaplan turbine unit. Name the different parts and state the purpose
served by each part.
(b) Explain how a centrifugal pump operates. [Dec 2004]

Q4(a) Describe with neat sketch, the construction and working of Francis turbine hydro-power unit.
(b) How do you classify the water pumps? Explain [May 2005]

Q5(a) Draw a schematic diagram of a Francis Turbine and explain its construction and working.
(b) How are centrifugal pumps classified? State the advantages of centrifugal pump over reciprocating pump?
[Dec 2005]

Q6(a) State the advantage and disadvantage of a Francis turbine over a Pelton wheel.
(b) How are centrifugal pumps classified?
(c) How does a volute casing differ from a vertex casing for the centrifugal pump? [May 2006]

Q7(a) State the advantages of a Kaplan turbine over Francis turbine.
(b) What are the functions of a draft tube?
(c) Explain with the help of neat sketch the working of a centrifugal pump. [Dec 2006]

Q8(a) Draw a schematic diagram of a Francis turbine and explain briefly its construction and working.
(b) How reciprocating pumps are classified.
(c) With the help of a neat sketch explain the working and principle of Hydraulic jack. [May 2007]

Q9(a) What is the functions of Hydraulic Lift. Discuss the construction and operation of hydraulic lift.
(b) A pelton wheel having semi-circular buckets functions under a head of 150 m and consume 50 litres per
sec of water. If 60 cm diameter wheel turns 600 revolutions per minute, make calculations for the power
available at the nozzle and the hydraulic efficiency of the wheel. [Dec 2007]

Q10(a) It is desired to generate 1000 kw of power and survey reveals that 450 m of static head and a minimum flow of 0.3 m3/sec is available. Comment whether the task can be accomplished by installing a pelton wheel that turns 1000 revolutions per minute and has an efficiency of 80%. Further design the pelton wheel by assuming suitable data for coefficient of velocity, speed ratio and velocity coefficient of the jet
(b)Difference between Impulse and Reaction hydraulic turbines. [May 2008]



GURGAON INSTITUTE OF TECHNOLOGY & MANAGEMENT, GURGAON
Semester: I Sem
Session: 2008-09
Department of Mechanical Engineering
Course Name: Elements of Mechanical Engineering
Course Code: ME-101-E
Assignment No.5
Faculty: R K Gupta
Professor
Q1(a) Derive an expression for the efficiency of a double purchase winch crab.
(b) The efficiency of a screw jack is 60%, when load of 2000N is lifted by an effort applied at the end of a
handle of length 75 cm. Determine the effort applied if pitch of the screw thread applied if pitch of the
screw thread is 100 mm. [Dec. 2003]
Q2(a) What is the effect of single start and multi start of thread in worm and worm wheel lifting machine on its
efficiency?
(b) A double purchase crab which has the following dimensions: Effective diameter of load drum = 150 mm,
length of handle = 400 mm, no. of teeth on pinions = 25 and 50, no. of teeth on spur wheels = 80 and 200.
When tested it was found that an effort of 100 N and 150 N were required to lift a load of 3000 N and
5000 N respectively. Determine:
i. the law of machine
ii. efforts to lift a load of 6000 N
iii. efficiency in the above case
iv. the maximum efficiency [May 2004]
Q3(a) Discuss the advantage and disadvantage of a double purchase winch crab over single purchase winch crab.
(b) Derive an expression for the maximum efficiency of a simple screw jack. [Dec 2004]
Q4(a) Establish a relation between the effort and load, when a square threaded screw is used for lifting purposes,
taking friction into account.
(b) Distinguish clearly the difference between the working of a single purchase winch and adouble purchase
winch crab. [May 2005]
Q5(a) State the condition for the reversibility and self locking of a machine.
(b) Describe second system of pulleys. Derive a relation for mechanical advantage and velocity ratio for the
system.
(c) In a simple wheel and axle, the radius of effort wheel is 240 mm and that of the axle is 40 mm. Determine
the efficiency, if a load of 300 N can be lifted by an effort of 60 N. [Dec 2005]
Q6(a) What are winch crabs? Sketch a single purchase winch crab and setup expression for its velocity ratio and
mechanical advantage would be affected when friction is taken into account?
(b) In a third system of pulleys there are 4 pulleys in all. Find velocity ration. Also find total load lifted by an
effort of 3200 N, if the efficiency of the machine is 75%. [May 2006]
Q7(a) With the help of neat sketch explain Third system of pulley. Also calculate Mechanical advantage and
velocity ration for the system.
(b) In a single purchase crab winch, length of handle is 200 mm and gear ration is 6. Find the Velocity ratio
and efficiency of the machine if a load of 5.4 KN is lifted by an effort of 300 N. Diameter of the drum is
100mm. [Dec 2006]
Q8(a) Explain the working of worm and worm wheel. Also make calculation for velocity ration, Mechanical
advantage and efficiency of the system.
(b) In a system where same rope constantly passes round all the pulleys, the load to be lifted is 1350 N and
effort is of magnitude of 400 N. The weight of the lower block is 50 N. If the number of pulleys is 4. Find
the efficiency of the system. [May 2007]
Q9(a) What do you mean by Reversible and Irreversible machines. Derive the condition for Irreversible machine.
(b) Derive V.R for Double purchase winch crab and single purchase winch crab. [Dec 2007]
Q10(a) Derive V.R for single start, double start and triple start worm & worm wheel and compare their results.
(b) Prove that ήmax = (1-sin¢)/ (1+sin¢) in case of Screw Jack, where ¢ is called angle of friction.
[May 2008]





GURGAON INSTITUTE OF TECHNOLOGY & MANAGEMENT, GURGAON
Semester: ISem
Session: 2008-09
Department of Mechanical Engineering
Course Name: Elements of Mechanical Engineering
Course Code: ME-101-E
Assignment No.6
Faculty: R K Gupta
Professor


Q1(a) Set up the following expression for the flat belt drive T1/T2 = eμθ , T1and T2 are the tensions on the tight
and slack sides of the belt; θ is the angle of contact and ; μ is the coefficient of friction between the belt
and the pulley rim.
(b) Enumerate the main types of toothed gears and point out their field of applications. [Dec. 2003]

2(a) What is clutch? Describe the working of a multi plate disc clutch (with a neat sketch) in power transmission.
(b) What is the difference between brake and dynamometer? Explain the working pf prony brake
Dynamometer. [May 2004]

Q3(a) What is meant by gear train? Name the different types of gear trains and state where each is used.
(b) Explain, with sketch, the band brake type dynamometer. [Dec 2004]

Q4(a) Why a clutch is necessary on a motor vehicle? Explain the working of a single plate clutch.
(b) What does a dynamometer measure? Explain clearly the difference between absorption and transmission
type of dynamometer. [May 2005]

Q5(a) What do you understand by gear train? Discuss various types of gera trains.
(b) List the advantage and disadvantage of belt drives.
(c ) Describe briefly a positive clutch. [Dec 2005]

Q6(a) Explain briefly an epicyclic gear train. What are the special advantages of epicyclic gear trains?
(b) What is a dynamometer? How does it differ from a brake?
(c ) Explain working and construction of Prony Brake Dynamometer. [May 2006]

Q7(a) List the uses of chain drives.
(b) How are friction clutches classified?
(c ) Explain briefly with a neat sketch a hydraulic brake system used in a motorcycle. [Dec 2006]

Q8(a) Explain briefly an epicylic gear train. What are the special advantages of epicylic gear trains?
(b) Explain with the help of neat diagram a belt transmission dynamometer. [May 2007]

Q9(a) Prove that for a flexible belt resting over the flat rim of stationary pulley T1/T2 = eμθ , where θ is called
angle of contact and μ is called coefficient of friction between belt & pulley.
(b) Discuss the various types of gears. [Dec 2007]

Q10(a) Prove that for crossed belt drive system the length of belt is given by l = π(r1 + r2) + (r1 + r2)2 /x + 2x.
r1 , r2 are radii of drive & driven pulleys x is the distance between centers of two pulleys.
(b) What do you mean by clutch? Discuss single plate clutch system with neat sketch. [May 2008]