PESIT - BANGALORE SOUTH CAMPUS
ELEMENTS OF MECHANICAL ENGINEERING – QUESTION BANK
Lathe / Milling / Drilling / Grinding
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Define a machine tool. (3)
Explain with a line diagram the principal parts of an engine lathe. (10)
With a neat sketch highlight the specifications of a lathe. (5)
Explain taper turning operations on lathe with neat sketches. (10)
Explain thread cutting operation on lathe with neat sketch. (5)
Explain the function of the following (a) Lead screw (b) Feed rod (c) Lathe dog (d) Chuck(e) Tailstock. (8)
What is drilling? Mention the different types of drilling machines (5).
Mention the different types of drilling machines. (5)
Explain the principle of working of a bench-drilling machine with a neat sketch. (10)
Draw a neat sketch of the radial drilling machine and explain its working. (10)
Name the various operations that can be performed on a drilling machine. (5)
Differentiate between (i) Drilling & Reaming
a. (ii) Boring & counter boring
b. (iii) Counter sinking & counter boring. (4x3=12)
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Explain with a neat diagram, principle of working of a milling machine. (10)
Differentiate between a typical lathe operation & milling operation
What is milling? Explain different operations commonly performed on a milling machine. (10)
Distinguish between up milling & down milling. (6)
Sketch & explain slab milling & slot milling process
Sketch & explain the working principle of i. Vertical milling machine, ii. Horizontal milling machine
Write short notes on:(a) Natural abrasives (b) artificial abrasives (c) Bonding materials. (5x2=10)
With a neat sketches explain the principle of:
(a) Surface grinding, (b) Cylindrical Grinding, (c) Centre less grinding.(5x3=15)
21 With a neat sketch explain the following lathe operations
i) Cylindrical turning
ii) Taper turning (8 Marks)
22 Explain with the sketch the principle of toper turning by swiveling the Compound rest. (8 Marks)
23 Explain the different types bonding of grinding wheels and the materials used. (6 Marks)
Soldering, Brazing, & welding
1. Explain the principle of welding. (4)
2. What is the difference between pressure welding & fusion welding? Explain with examples. (5)
3. Explain the arc welding process. (4)
4. Explain the process of gas welding. (5)
5. Explain with sketch different oxy-acetylene gas welding flames & their respective application.
6. Differentiate between arc welding and Gas welding (6).
7. Explain soldering. What fluxes are commonly used in soldering? Why is the flux necessary? (6)
8. What is brazing? Explain.
9. Compare welding, soldering, and brazing. (6)
10. Compare brazing and soldering. (4)
Lubrication and Bearings
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Why lubrication is necessary in bearings and moving parts of a machine. (5)
What are the different types of lubricants? (5)
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Explain the properties of a good lubricant. (5)
Define: Viscosity, Flash point, Fire point, Specific gravity, Volatility, Oiliness & wettability, Cloud
point, pour point.(8)
5. What are the different methods of lubrications? (4)
6. Describe the following methods of lubrication with neat sketches, (a) Wick lubrication (b) Ring oiling
(c) Splash lubrication (d) Glass bottle needle type lubricator. (5x4=20)
7. Define bearing. What are the main types of bearings? (4)
8. Sketch and name the different parts of the following bearing: (a) Bushed bearing (b) Plummer block
(c) Foot step bearing (d) Ball bearing (e) Roller bearing. (4x5=20)
9. Explain the constructional features of a thrust ball bearing with a neat sketch. Where is it used? (5)
10. What are the advantages and disadvantages of anti friction bearings? Give their applications. (5)
11. Explain with sketches the operation of sliding contact and rolling contact bearings with examples. (5)
12. What are the advantages and disadvantages of ball and roller bearings over Journal bearings? (6)
13 Draw a neat sketch of a drop feed lubrication method and explain its working. (8)
I C Engines
1.
What is an IC engine? How is it different from an external combustion engine? (4)
How are they classified? (4)
2. Sketch & briefly explain the main parts of a typical IC engine? What are their functions? (5)
3. Explain with P-V diagram, the working of a (i) Four-stroke petrol engine (ii) Four stroke diesel engine
iii) Two stroke petrol engine (iv) Two stroke diesel engine. (10x4)
4. Define the following terms: (a) Indicated power (b) Brake power (c) Mechanical efficiency of an IC engine.
(6)
5. Define indicated thermal efficiency and brake thermal efficiency. (5)
6. Distinguish between: (i) 2-stroke and 4-stroke IC engine. (ii) Diesel engine and petrol engine 5x2=10
7. What are the advantages of: (a) 2-stroke engine over 4- stroke engine. (b) Diesel engine over petrol engine.
(5x2=10)(c) With a neat sketch explain the construction and working of 4 - stroke diesel engine. (10
Marks)
8. Sketch & explain the working of : i) Simple carburetor ii) Fuel injector
9. A 2 – stroke IC engine has a piston diameter of 150 mm. And average piston speed is 3.5 m/sec. If the MEP
is 0.786 M Pa, find the indicated power of the engine. (5)
10. A 4-stroke engine has a piston diameter of 110mm. and stroke length of 140 mm. The MEP is 6 bar. Find
the indicated power, if it runs at a speed of 1000 RPM. (5)
11. The brake wheel of an engine runs at 300 RPM and is 500 mm in radius. The spring balance pull is 0.2
times the dead load. Find the dead load if the brake power is 16.5 KW. (5)
12. The following details refer to a 4 stroke engine: Cylinder dia = 200mm, stroke = 300mm, speed = 300
RPM, Effective brake load = 50 kg., Mean circumference of the brake wheel = 400mm, MEP = 6 bar,
calculate, IP, BP & Mechanical efficiency. (10)
13. A single cylinder, two stroke cycle IC engine has a piston of diameter 105 mm, and stroke length 120 mm.
The mean effective pressure is 6 bar. If the crankshaft speed is 1500 RPM, calculate the indicated power of
the engine. (5)
14. A single cylinder, four stroke IC engine has a bore of 180mm. Stroke of 200 mm, and has a rated speed of
300 Rpm. At full load the torque on the brake drum was 200 N-m, and 4 kg., of fuel was consumed in one
hour. If the calorific value of the fuel is 42,000 KJ/kg. Calculate the brake power, indicated power,
mechanical efficiency, indicated thermal efficiency and brake thermal efficiency.
15. A 4-stroke IC engine running at 450 rpm has a bore diameter of 100 mm and stroke length of 120 mm. The
indicated diagram details are; area of the diagram 4 cm2, length of indicated diagram 6.5 cm and the spring
value of the spring used is 10 bar/cm. Calculate the indicated power of the engine.
16. A single cylinder four-stroke engine runs at 1000 rpm, has a bore of 115 mm, and has a stroke of 140 mm.
The brake load is 60 N at 600 mm radius and the mechanical efficiency is 80%. Calculate brake power and
mean effective pressure. (5)
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17. A four stroke six cylinder gas engine with a stroke volume of 1.75 x 10 -3 m3 develops 25 kW at 500 rpm.
The mean effective pressure is 6 bar. The mechanical efficiency is 80%. Find I.P. and the braking torque on
the brake drum (10)[26.25kW, 401 N-m]
18. List the advantages of fuel injection
19. A four stroke diesel engine has a piston diameter 200 mm and stroke 300 mm. It has a mean effective
pressure of 2.75 bar and a speed of 400 rpm. The diameter of the brake drum is 1000 mm, and the
effective brake load is 32 kg. Find the indicated power, brake power, and frictional power of the
engine. [15.45kw, 12.36kw, 3.09kw]
19. A person conducted a test on a single 'Cylinder two stroke petrol engine and found
that the mechanical and brake thermal efficiencies of the engine were 0.7 and 0.2 respectively. The
engine with a mean effective pressure of 6 bar ran at 300 Rev/min consuming fuel at a rate of 2.2kg/h.
Given that the calorific value of the Fuel is 42.500 kJ/kg and that the stroke to bore ratio of the engine
Cylinder is 1.2. Find the bore and stroke of the engine in mm. (10 Marks)
21. Draw a neat sketch of a water tube boiler and explain its working. (10 Marks)
Refrigeration & Air Conditioning
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Define the terms: Refrigeration and refrigerant. (6)
Explain basic concepts of refrigeration and the requirements of a good refrigerant (5).
Define C.O.P. of a Refrigerator (3)
Explain with a neat block diagram the working of vapor compression refrigerator. (10)
Explain with a neat block diagram the working of vapor absorption refrigerator. (10)
Write a short note on (a) Kinds of refrigerants commonly used
(b) Properties of a good refrigerant. (5x2=10)
7. Explain the basic principle of Air –conditioning. (5)
8. What is the difference in the basic principle of working of vapor compression and vapor absorption
refrigerators?
9. Define humidity, absolute humidity, relative humidity, and temperature-humidity index.
10. Name the commonly used refrigerants
(a) Explain the properties of a good refrigerant. (4 Marks)
(b) With a neat sketch explain the working of vapor compression refrigeration. (8 Marks)
11 (a) What is the difference between refrigeration and air conditioning? Explain ( 4 Marks).
12 Define 'Refrigerating Effect' and 'Co-efficient of Performance' of a
Refrigerating system. What do you mean by the statement " ton of
Refrigeration"? How do you classify the Freon group of refrigerants? Explain.
(06 Marks)
Sources of Energy
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Differentiate between Renewable & Non renewable sources of energy. Give examples for each
Why is there a need to harness renewable sources of energy? What are the advantages of using Renewable
energy sources?
What are the advantages & disadvantages of Conventional energy usage over Non Conventional energy?
List different sources of Non Conventional energy. Explain briefly how energy is generated in each of the case.
Also list their advantages & disadvantages
List different forms of Solar energy utilization
Write short notes on: a) Solar Energy, b) Wind Energy, c) Tidal Energy, d) Ocean Thermal Energy, e)
Geothermal Energy, and f) Nuclear Energy
Name the different mediators and coolants used in the nuclear reactor and mention their functions
What are advantages and disadvantages of:
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a) Hydro-electric power plants, b) Solar energy, c) Wind energy, d) Tidal power, e) Ocean thermal energy, & f)
Nuclear power plant
9. Explain the following:
i) Conventional and Non-conventional energy sources
ii) Solar energy utilization.
10. What is Ocean Thermal Energy Conversion (OTEC)?With the help of a simple sketch
Explain how power can be obtained using OTEC plants? (6 Marks)
11. 2 kg wet steam is heated at a constant pressure of 2 bars until its temperature
increases to 150°C. The heat transferred is 2100kJ. Find the initial dryness fraction
of steam. Assume C .steam = 2.1kJ/kgK. If required use the extract of the steam
table provided below.
Extract of Saturation Steam Table
(8 Marks)
.
12. Explain fusion and fission processes for power generation. (06 Marks)
13 Explain the three principal solar energy conversion processes. (06 Marks)
Properties of Steam & Boilers
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Define the terms: wet steam, dry steam, and super heated steam. (3)
Explain the terms: dryness fraction, sensible heat, and latent heat of vaporization. (6)
What are the advantages and disadvantages of super heated steam? (4)
What is enthalpy? Show that in constant pressure process change in enthalpy of steam is equal to the total heat
supplied. (5)
Calculate the enthalpy of steam at a pressure of 30 bar absolute if: i) Its dryness fraction is 0.75 & ii) It is
superheated to 4000 C (6)
[353.8 kj/kg, 3217.7kj/kg]
A steam initially will be at 9 bar and dryness of 0.98. Find the final quality and temperature of the steam at each
of the following operations: (a) when the steam loses 50 KJ/Kg at constant pressure (b) when the steam receives
100 KJ/Kg at constant pressure (5). [Ans:0.955 & 240º C]
A sample of 1 kg. Of super heated steam at 7 bar contains 3000 KJ. Find the super heat content of the steam. If
500 KJ of enthalpy is spent in doing an external work, what will be the enthalpy of steam? (5)
What is the enthalpy of 5 kg of steam in the following conditions? a) 0.8 bar and 90% dry. b) 20 bar and
superheated to 300º C (5)
[12192.05 kJ, &14971.8kJ]
Find enthalpy required to produce 5 kg. of dry saturated steam at 6 bar from water at 30º C. (5)
0.2 kg. Of steam with an initial dryness fraction of 0.7 is heated at constant pressure of 7 bar till temperature
rises to 250º C. Calculate the enthalpy required. Assume Cp= 2.25kJ/kg-K. (5) [162.17 kj]
The enthalpy of 1 kg. of steam at 8 bar pressure is 2373.5 KJ/Kg. Find the condition of the steam. (5)
The specific volume of steam at 10 bar is 0.2428 m3/kg. What is the condition of the steam? (5) [Ans: 292.95º
C]
Find the specific volume and enthalpy of 1 Kg of steam at 0.8 M Pa: (a) when the dryness fraction is 0.9 and (b)
when the steam is superheated to a temperature of 300 0 C. The specific heat of superheated steam is 2.25
KJ/Kg. (10)
By actual measurement the enthalpy of a saturated steam at 1900 C is 2500 kJ/kg. What is the quality of the
steam? (5) [0.856]
Determine the external work done during evaporation of water at 25 bar absolute pressure into steam of dryness
fraction 0.84 (4)[167.81kj/kg]
For a sample of steam a pressure of 8 bar absolute and 0.9 dry, calculate:
i) External work of evaporation & ii) Internal latent heat(6)[173kJ/kg,1668.9kJ/kg]
What is a Boiler? List the essential parts of a Boiler (5)
PESIT BANGALORE SOUTH CAMPUS education for the real world
18. Differentiate between: a) Water tube boiler & fire tube boiler. b) Externally fired & internally fired boiler. c)
Boiler mountings & boiler accessories. (5x3 =15)
19. What are the advantages and disadvantages of water tube boilers over fire tube boilers? (5)
20. Explain the working of a Lancashire boiler with a neat sketch. (10)
21. Explain the working of a Babcock and Wilcox boiler with a neat sketch. (10)
22. List the important boiler mountings and mention their functions. (5)
23. Explain clearly the functions of safety valve and feed check valve in a boiler.(5)
24. Calculate the specific volume of steam at 2500 C and dryness fraction of 0.8 (5)
[0.04003 m3/kg]
25. Determine the density of steam initially at 17 bar having a dryness fraction of 0.8. If 300 kJ/kg of heat are
supplied at constant pressure, determine the condition, density and enthalpy (10)
[10.72 kg/m3, 0.956 dry, 8.97 kg/m3, 2709.08 kJ/kg]
Turbines
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Define a steam turbine. How are they classified? (4)
Explain the working of an impulse turbine. (4)
Explain the working of a reaction turbine. (4)
What are the differences between an impulse turbine and a reaction turbine? (5)
List down at least five important advantages of steam turbines over other prime movers. (5)
Explain the working principle of a gas turbine? How is a Gas Turbine different from a steam Turbine?
Explain with neat sketch open & closed cycle gas turbine. Mention their specific differences
What are the advantages & disadvantages of closed Gas turbine cycle over the open cycle?
Enumerate the applications of Gas Turbine
Give a brief classification of water turbines
Differentiate between Impulse & reaction water turbines. Give examples for each. Under what specific
conditions o f head & discharge are Impulse & reaction turbines used
37. Explain with neat sketch, the working principles of
i) Pelton Turbine
ii) Francis Turbine
iii) Kaplan Turbine (10)
Power transmission
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What are the different methods of transmitting power from one shaft to other?(4)
What is a belt drive? Explain how open belt drive and cross belt drive function.(5)
With a neat sketch explain Fast and Loose pulley and speed cone pulley. (6)
What is slip? Explain. (4)
What is creep? Explain. (4)
What are the advantages of V belt over flat belts? (5)
Distinguish between belt and chain drives. (5)
Mention the specific application of chain drive. What is their major advantage over a belt drive
Sketch & explain the applications of. (I) Spur gears (ii) Helical gears (iii) Worm and worm wheel (iv) Rack
and pinion (v) Bevel gear. (5)
What is gear train? What are the different types of gear trains? (5)
Differentiate between simple and compound gear trains. (5)
It is required to a drive a shaft A at 600 rpm by a belt using a pulley of 150 mm diameter on another
parallel shaft B running at 240 rpm. What would be the diameter of the pulley on the shaft A? Find also the
velocity ratio. (5)
13.A motor runs a lathe at 400 rpm. The diameter of the motor pulley and lathe pulley are 0.2 m and 0.6m
respectively. Find the velocity ratio and the speed of the motor. (5)
In a belt drive, the ratio of the tensions may be assumed as 2 and the slack side tension is 500 N. If the
speed and the diameter of the driven pulley are 200rpm and 120mm. respectively, find the power
transmitted. (10)
The speeds of the driving and driven pulleys are 180rpm and 300 rpm respectively. If the sum of the
diameters of the pulleys are 1040 mm. Find the diameter of each and the linear speed of the belt in m/sec.
(5)
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16. A gear wheel having 40 teeth and running at 100 rpm is driving another gear wheel having 20 teeth. Find
the speed of the driven gear wheel. (5)
17. Two parallel shafts are connected by spur gears. The speeds of the driving and driven wheels are 180rpm
and 120rpm respectively. If the number of teeth on the driving wheel is 100, find the number of teeth on the
driven wheel. (5)
[67, 105:1]
18. A simple train of wheel consists of three wheels having number of teeth 40, 50, and 70 respectively. Find
the velocity ratio. If the driving wheel having 40 teeth is running at 210rpm, find the speed of the driven
wheel.(5)
[120rpm]
19. In a compound gear train of wheels A, B, C & D have 15, 30,20 & 40 teeth respectively, the wheels B & C
are keyed to the same spindle. If the wheel A runs at 400 rpm, find the speed of the wheel D. Sketch the
arrangement. (5)[100 rpm]
20. An engine shaft running at 200rpm is required to drive a generator at 300 rpm by means of flat belt drive.
Pulley on the driving shaft has 500mm. diameters. Determine the diameter of the pulley on the generator
shaft if the belt thickness is 8 mm. and slip is 4%. (5)
21. Derive an expression for the ratio of tensions in the belt in terms of regular notations, T1, T2, µ, Ø. (10)
22. A compound gear train is formed by 4 gears P, Q, R & S. Gear P meshes gear Q and gear R meshes gear S.
Gears Q and R is compounded. P is connected to the driving shaft and S is
23. Connected to the driven shaft and power is transmitted. The details of the gears are:
a. Gears:
P
Q
R
S
b. No. of teeth :
30
60
40
80
24. If the gear S were to rotate at 60 rpm. Calculate the speed of P. Represent gear arrangement schematically.
(6)
25. 23. A simple gear train consists of three gears. The number of teeth on the driving gear is 60, on the idler is
40 and the number of teeth on the driven gear is 80. Find the velocity ratio. If the driving gear is rotated at
1200 rpm. Calculate the speed of the driven gear.
[4:3, 900 rpm]
26 Derive an expression for ratio of tensions in belts.
(8 Marks)
27 With a block diagram explain the open loop control system. (4 Marks)
28 In a belt drive, the velocity ratio is3. The driving pulley runs at 400rpm. The diameter
of the driven pulley is300mm: 'Find the speed of the driven pulley and the diameter
of the driving pulley. (6 Marks)
29. Show the different elements on the cross-sectional view of V-Belt.
30 What are the advantages of V-Belt over Flat Belts? (05Marks)
31 Explain with neat diagram the pin type flexible coupling.
PESIT BANGALORE SOUTH CAMPUS education for the real world