BT-203 Basic Mechanical Engineering - Jun 2024 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aDraw $Fe$-$Fe3C$ phase diagram and explain the phase transformation reactions in the diagram.
   How to answer

   • Draw labelled Fe-Fe3C diagram with temperature vs %C axes
   • Mark phases: ferrite, austenite, cementite, pearlite, ledeburite
   • Explain peritectic, eutectic and eutectoid reactions with equations
   • Mention critical temperatures and carbon compositions
2. 7 Marks
   bDefine the following Mechanical properties of materials. i) Strength ii) Hardness iii) Toughness iv) Ductility v) Brittleness vi) Malleability
   How to answer

   • Define strength as resistance to failure under load
   • Define hardness, toughness, ductility, brittleness, malleability
   • Distinguish with one-line mechanical meaning for each
   • Give example or test where relevant
3. 7 Marks
   aDescribe the typical shape of the stress-strain curve for a ductile material. Explain the significance of the yield point and ultimate tensile strength on the stress-strain curve of a ductile material.
   How to answer

   • Sketch typical stress-strain curve for mild steel
   • Mark proportional limit, elastic limit, yield point, UTS, fracture
   • Explain yield point significance - onset of plastic deformation
   • Explain UTS significance - maximum stress, necking after
4. 7 Marks
   bState and explain various types of errors in measurements.
   How to answer

   • Define measurement error and classification
   • Explain systematic errors with types
   • Explain random errors and gross errors
   • Explain methods to minimize errors
5. 7 Marks
   aList out various operations performed by Lathe and explain some of them in detail.
   How to answer

   • List lathe operations: turning, facing, taper turning, threading, drilling, boring, knurling etc.
   • Explain construction and tool-work motion briefly
   • Explain some operations like turning, taper turning, threading in detail
   • Give applications
6. 7 Marks
   bList out various Temperature measuring instruments and explain any two with neat diagram.
   How to answer

   • List temperature instruments: thermocouple, RTD, pyrometer, thermistor, bimetallic thermometer
   • Explain principle of any two
   • Draw neat labelled diagram of each
   • Mention applications and range
7. 7 Marks
   aDescribe the working principle of hydraulic pumps. Give classification of pumps with their applications.
   How to answer

   • Explain hydraulic pump principle - mechanical to hydraulic energy
   • Classify positive displacement vs roto-dynamic, reciprocating vs rotary
   • List types: gear, vane, piston, centrifugal pumps
   • Give applications of each type
8. 7 Marks
   bDerive Bernoulli's equation for incompressible fluids.
   How to answer

   • State assumptions: steady, incompressible, inviscid flow along streamline
   • Apply energy conservation to fluid element
   • Derive $p/\rho g + V^2/2g + z = constant$
   • Mention limitations and applications
9. 7 Marks
   aWhat is Pascal's law, Explain how Pascal's law is applied in hydraulic systems?
   How to answer

   • State Pascal's law - pressure transmitted equally in confined fluid
   • Explain formula $F1/A1 = F2/A2$ for force multiplication
   • Explain application in hydraulic jack, press, brake
   • Draw schematic of hydraulic system
10. 7 Marks
    bWhat are the main types of boilers, and how are they classified based on construction and operation?
    How to answer

    • Define boiler and its function
    • Classify by fire-tube vs water-tube, horizontal/vertical, natural/forced circulation
    • Classify by pressure, fuel, construction and operation
    • Give examples like Babcock-Wilcox, Lancashire boiler
11. 7 Marks
    aExplain the concept of draught in boiler operation. Discuss the factors influencing the choice between natural and artificial draught systems in boiler installations.
    How to answer

    • Define draught - pressure difference for air and flue gas flow
    • Explain natural vs artificial draught
    • Discuss factors: chimney height, fuel type, boiler capacity, efficiency
    • Compare selection criteria for installations
12. 7 Marks
    bExplain thermodynamic processes at constant pressure and volume.
    How to answer

    • Define thermodynamic process and state
    • Explain constant pressure (isobaric) process with $p-V$ diagram
    • Explain constant volume (isochoric) process with $p-V$ diagram
    • Give work and heat expressions for both
13. 7 Marks
    aWith a neat sketch, explain the working of Carnot and derive the expression for thermal efficiency.
    How to answer

    • Draw p-V and T-S diagrams of Carnot cycle
    • Explain four processes: two isothermal, two adiabatic
    • Derive efficiency $\eta = 1 - T2/T1$
    • State assumptions of reversible engine
14. 7 Marks
    bExplain the Working principle of compressor with neat sketch.
    How to answer

    • Define compressor and its purpose
    • Draw neat sketch of reciprocating/rotary compressor
    • Explain suction, compression and delivery strokes
    • Mention applications
15. 7 Marks
    aExplain the working of a 2 stroke petrol engine with neat sketch.
    How to answer

    • Draw labelled sketch of 2-stroke petrol engine
    • Explain scavenging, compression and power-exhaust processes
    • Explain role of ports vs valves
    • Show cycle on diagrams
16. 7 Marks
    bWrite short notes on Slip gauge, Sine-bar and Combination set.
    How to answer

    • Define slip gauge and its use for precision length
    • Describe sine-bar principle $\sin\theta = h/L$ with diagram
    • Describe combination set components and uses
    • Mention applications in metrology