DME
TUTOR MARKED ASSIGNMENT
BME-032
REFRIGERATION AND AIR CONDITIONING (RAC)
Maximum Marks : 100
Weightage : 30%
Course Code : BME-032
Last Date of Submission : October 30, 2014
Note : All questions are compulsory and carry equal marks.
Q.1 (a)
(b)
Write in brief the applications of refrigeration and air conditioning in various industries.
Describe in brief the functions of following components in a refrigeration system :
(i)
Compressor,
(ii)
Condenser,
(iii)
Receiver,
(iv)
Expansion valve, and
(v)
Evaporator.
(4 + 6 = 10)
o
o
Q.2 (a)
908 kg of water at 0 C is converted into ice at 0 C in 24 hours in a refrigerating
machine. Calculate the capacity of machine in tons of refrigeration (TR).
(b)
Draw the simple vapour compression cycle on p-h diagram and discuss and explain
each forces.
(c)
Draw a vapour compression system with liquid-vapour heat exchanger (LVHX). Draw
its cycle on p-h diagram and discuss the effect of using liquid-vapour heat exchanger
on refrigerating effect, compressor work, suction vapour specific volume and COP of
the cycle.
(3 + 3 + 4 = 10)
Q.3 (a)
Show that COP of reversed cycle can be expressed as :
COP 
T1
T2  T1
where T1 is lower temperature and T2 is higher temperature.
(b)
Draw the schematic diagram of a multistage vapour compression system and its cycle
on T-S diagram. List the advantages of using a multistage system.
(c)
Describe the effects of liquid sub-cooling on the performance of simple vapour
compression cycle.
(4 + 3 + 3 = 10)
Q.4 (a)
Draw the single stage lithium bromide water vapour absorption system and explain its
working.
(b)
Write the chemical formula of the following refrigerants : R 12, R 22, R 115 and R 134.
(c)
List desirable chemical and physical properties of refrigerants.
(5 + 2 + 3 = 10)
1
Q.5 (a)
Describe the working of float valves. How a low side float differs from high side float
valve?
(b)
How does a thermostatic expansion valve work? Describe its functions in brief.
(c)
Describe the construction of a centrifugal compressor with the help of a suitable
diagram and write in brief the functions of its various components.
(4 + 3 + 3 = 10)
o
o
Q.6 (a)
A Carnot refrigerator absorbs heat at 0 C and rejects heat at 27 C. If the refrigerator
consumes power at a rate of 0.5 kW, calculate the heat absorbed by refrigerator at 0oC
in kW. How much heat is rejected by refrigerator at 27oC.
(b)
Describe the working of screw compressor. In which conditions, a screw compressor is
preferred?
(5 + 5 = 10)
Q.7 (a)
A vapour compression machine produces 15 TR. The refrigerant is R 12. The
evaporator temperature is – 10oC and condenser temperature is 40oC. Using
refrigerant tables or charts, calculate (i) mass flow rate of refrigerant, (ii) refrigerating
effect, (iii) heat rejected in condenser and (iv) COP.
(Hint : Mass flow rate 
(b)
3.52  TR
).
Refrigerating effect
Describe the Ewing’s method to find suction state for maximum COP.
(6 + 4 = 10)
Q.8 (a)
Write the definition of specific humidity and derive the following expression :
w  0.622
p
p  p
(b)
Define relative humidity and write its expression. If the value of relative humidity is
100%, what will be the relation between DBT and WBT?
(c)
Show different constant property lines on psychometric chart. How many properties are
required to describe the state of moist air?
(4 + 3 + 3 = 10)
Q.9 (a)
What is the purpose of cold storages? On what basis inside design conditions for cold
storages are decided? Describe in brief.
(b)
List different types of freezers used for freezing of fruits and vegetables. Describe air
blast freezer and its working.
(c)
Describe the process of freeze drying and writs its applications.
(3 + 4 + 3 = 10)
Q.10 Write short notes on the following :
(i)
Global warming caused by refrigerants,
(ii)
Comfort air conditioning,
(iii)
Rotary compressors, and
(iv)
Refrigeration in breweries.
(2.5  4 = 10)
2
DME
TUTOR MARKED ASSIGNMENT
BME-060
MACHINE DESIGN
Maximum Marks : 100
Weightage : 30%
Course Code : BME-060
Last Date of Submission : October 30, 2014
Note : All questions are compulsory and carry equal marks.
Q.1 (a)
(b)
Write and explain the qualities of a ‘Designer’.
Discuss in detail the process of design procedure.
(5 + 5 = 10)
Q.2 (a)
What do you understand by fatigue strength and enumerate factors that affect fatigue
strength?
(b)
A cast iron column of hallow circular cross-section is to support a load of 10.16 tonnes
with a factor of safety 8. The ends of the column may be considered fixed. If the length
of the column = 6.09 m and the internal diameter = 4/5 of external diameter. Calculate
1
the external diameter. Use Rankine formula, fc = 56.7 kg/mm2 and a 
.
6400
(5 + 5 = 10)
Q.3 (a)
(b)
Describe three parts of cotter joints and sketch them separately.
A cotter joint is required to carry 40 kN axial force. Following dimensions have been
found :
Diameter of spigot, d1 = 38 mm
Diameter of socket collar, D2 = 80 mm
Width of cotter at mid section = 50 mm
Thickness of cotter = 15 mm
Calculate the bending stress in cotter.
(5 + 5 = 10)
Q.4 (a)
(b)
Describe types of riveted joints. What are different types of failure of riveted joints?
What is back pitch of a riveted joint? What is the allowable load for a riveted joint?
A simple-riveted but joint is made up of 12.7 mm thick main plates and two cover
plates, each 9.5 mm thick. The rivet diameter is 20.6 mm and the pitch of the rivet is
76.2 mm. The ultimate stresses recommended are : 3850 kg f/cm2 in tension,
6650 kg f/cm2 in compression and 3080 kg f/cm2 in shear. Assuming a factor of safety
of 5 in each case, determine the allowable load that can be imposed on the joint.
(5 + 5 = 10)
Q.5 (a)
(b)
What types of joints are used in a boiler along its length and circumference and why?
What do you understand by eccentric loading of riveted joint? Explain with the help of
sketch.
(5 + 5 = 10)
3
Q.6 (a)
(b)
What is welded joint? Describe types of welded joints.
Sketch a T-joint and show how it can be loaded. What stresses will be induced in the
weld?
(5 + 5 = 10)
Q.7 An eccentrically loaded plate is welded to a frame as shown in Figure 1. Design the welded
joint if the tensile stress in the weld is not to exceed 9 kg f/mm2.
la
50
6T
80
lb
Figure 1
(10)
Q.8 Distinguish between square and Acme threads, the Acme threads and the V-threads. What
reasons you can put forth for preferring the Acme threads to square threads?
(10)
Q.9 A square threaded screw is required to work against an axial force of 8.0 kN and has
following dimensions :
Major diameter d = 36 mm, pitch p = 6 mm with single start,  = 0.08. Axial force rotates with
the screw.
Calculate :
(i)
Torque required when screw moves against the load.
(ii)
Torque required when screw moves in the same direction as the load.
(iii)
Efficiency of the screw.
(10)
Q.10 (a)
Describe materials for shafts. What are the loads that come upon shafts? How will you
calculate load upon a shaft if it supports a pulley or when it supports a gear?
(b)
What is stiffness of shaft in bending and torsion? How do you consider the deflection
and twist in design of shaft?
(5 + 5 = 10)
4
DME
TUTOR MARKED ASSIGNMENT
BME-061
AUTOMOBILE ENGINEERING
Maximum Marks : 100
Weightage : 30%
Course Code : BME-061
Last Date of Submission : October 30, 2014
Note : All questions are compulsory and carry equal marks.
Q.1 (a)
How vehicles are classified on the basis of their body and load?
(b)
Explain the working of a two stroke diesel engine with the help of suitable sketches.
(c)
Explain the following terms :
(i)
Power stroke,
(ii)
Scavenging, and
(iii)
Stroke volume.
(3 + 3 + 4 = 10)
Q.2 (a)
What are different requirements of an ignition system? State briefly.
(b)
Sketch battery ignition system and explain how does it work?
(c)
Write the functions of the following :
(i)
Condenser, and
(ii)
Ignition switch.
(3 + 4 + 3 = 10)
Q.3 (a)
Sketch a can type ignition coil and describe its working. What is its function in the
starting system of an automobile?
(b)
What is the working principle of a dynamo? Explain its working by giving a neat sketch.
(c)
What function is performed by a vacuum advance mechanism? Explain how does it
work?
(4 + 3 + 3 = 10)
Q.4 (a)
List the main parts of a clutch and write its various functions.
(b)
What is the difference between sliding mesh and constant mesh gear box? List the
advantages of the later over the former.
(c)
A simple gear train consists of three gears each of which is mounted on a separate
shaft. The three shafts are parallel to each other. The driver (Gear 1) rotates at
2000 rpm. Gear 2 is driven by Gear 1 and Gear 3 is driven by Gear 2. The number of
teeth on Gears 1, 2 and 3 are 40, 60 and 100. Determine the :
(i)
Speed ratio of gear train,
(ii)
Speed of follower, i.e. Gear 3, and
(iii)
Direction of rotation of Gear 3 if Gear 1 rotates in anticlockwise direction.
(3 + 3 + 4 = 10)
5
Q.5 (a)
Describe the function and operation of final drive.
(b)
How rear axles help in transmitting power to wheels? List different types of rear axles
and explain working of one of them.
(c)
Write the function of the following parts where are they used?
(i)
Slip joint, and
(ii)
Ball and trunnion joint.
(4 + 3 + 3 = 10)
Q.6 (a)
(b)
What is the difference in the working of the following brakes :
(i)
Air brakes,
(ii)
Vacuum brakes, and
(iii)
Electric brakes.
Write short notes on the following :
(i)
Mechanical brakes, and
(ii)
Adjustment of brakes.
(5 + 5 = 10)
Q.7 (a)
Describe stub axles and list different types of stub axle.
(b)
Explain steering geometry of a four wheeler with the help of a neat sketch.
(c)
Why caster angle is provided in the vehicles? Explain this term with the help of a neat
sketch.
(d)
Describe the layout of a steering system.
(2 + 2 + 2 + 4 = 10)
Q.8 (a)
What is ‘king pin inclination’? Why it is provided in the automobiles?
(b)
Describe worm and sector type steering gear.
(c)
Which factors are responsible for vehicle stability during steering? Explain with
reasons.
(3 + 3 + 4 = 10)
Q.9 (a)
List and draw different types of sections used in making frames. For which types of
loads, different sections are best suited?
(b)
What for springs are used in suspension system of automobiles? Describe various
types of springs.
(c)
How does a shock absorber helps to arrest the vibrations of vehicles? Discuss its
principle and operation in brief.
(3 + 4 + 3 = 10)
Q.10 (a)
How can we reduce the tyre wear? List different remedies for reducing tyre wear.
(b)
How tyres are specified? Describe with the help of an example.
(c)
Describe some recent developments in the area of passenger cars, e.g. ABS, etc.
(3 + 3 + 4 = 10)
6
DME
TUTOR MARKED ASSIGNMENT
BME-062
METROLOGY AND INSTRUMENTATION
Maximum Marks : 100
Weightage : 30%
Course Code : BME-062
Last Date of Submission : October 30, 2014
Note : All questions are compulsory and carry equal marks.
Q.1 What is a sine bar? Explain its use with the help of a dial indicator.
Q.2 What is the relationship between sensitivity and range? What is disadvantage of very
sensitive instruments?
Q.3 A vernier scale consists of 25 divisions on 12 mm spacing and the main scale has
24 divisions on 12 mm. what is the least count?
Q.4 Sketch and describe the working principles and uses of the following :
(i)
outside micrometer, and
(ii)
inside micrometer.
Q.5 Describe the uses of :
(i)
Slip gauges, and
(ii)
Angle gauges for measuring and comparing lengths and angles.
Q.6 What points you will keep in mind in selecting the tolerance between the piston and cylinder
of a steam engine?
Q.7 (a)
(b)
Q.8 (a)
(b)
Describe in brief the principle of auto collimator with the help of a neat sketch.
Sketch a vernier level protector and explain the different parts.
What is the difference between relative error, random error and systematic error?
One manufacturer of a coordinate measuring machine has indicated its accuracy as :
3 accuracy :  0.003 mm
2 accuracy :  0.002 mm
1 accuracy :  0.001 mm
What do you understand by the statement?
Q.9 (a)
(b)
What is fit? Name the three main types of fits with their uses and suitable sketches.
State the importance of limits and fits in large-scale production.
Q.10 Explain the following terms :
(i)
Tolerance,
(ii)
Allowance,
(iii)
Basic Size,
(iv)
Standard Size, and
(v)
Normal Size.
7
DME
TUTOR MARKED ASSIGNMENT
BME-063
CAD/CAM
Maximum Marks : 100
Weightage : 30%
Course Code : BME-063
Last Date of Submission : October 30, 2014
Note : All questions are compulsory and carry equal marks.
Q.1 (a)
(b)
Q.2 (a)
(b)
Q.3 (a)
(b)
Q.4 (a)
Define CAD and list out the benefits of CAD.
What is visualization of the model? How do you display the model? Explain with
suitable examples.
What are the input devices applied in CAD system? Explain.
What is solid modeling? Explain the various methods of solid modeling with suitable
examples.
Explain the working of CRT graphic display device with suitable sketch.
What are the basic techniques for generation of graphic image? Explain any approach
with suitable examples.
What are the output devices applied in CAD system? Explain.
(b)
Why 3D modeling is important? Explain the limitation of wire-frame modeling over solid
modeling.
Q.5 (a)
What are the basic components of CAD? Explain the implementation of typical CAM
process on a CAD/CAM system with suitable block diagram.
(b)
Q.6 (a)
(b)
Q.7 (a)
(b)
Q.8 (a)
(b)
Q.9 (a)
(b)
Q.10 (a)
(b)
What is CNC? Explain the working of CNC system with suitable block diagram.
What are the types of system used to control the motion in NC system? Explain.
What are the types of coordinate system? Explain any one method with suitable
examples.
What is FMS? Describe the concept of FMS with neat sketch.
List out the various advantages and disadvantages of CNC mechanics.
What is servomechanism? Explain the working of servomechanism in CNC machine
with suitable sketch.
List out the advantages and disadvantages of FMS.
What is MIS? Explain the concept of MIS with suitable sketch.
List out the various problems facing in FMS.
Define Robotics. Explain the various parameters and working principle of industrial
robot.
List out the various application of decision support systems (DSS).
8