BME semester examination winter 2019 (vgec)
BE 1st-semester examination winter 2019
subject code 311006 Date:18/11/2019
subject name: Basic Mechanical Engineering
Time: 1 hour Total marks: 15
Q.1(A) State all three laws of thermodynamics. Explain Zeroth law of thermodynamics in detail.[3]
Q.2(A) Calculate the mass of 0.2 m3 of steam at 10 bar pressure having dryness fraction of 0.7. Also calculate enthalpy, internal energy of 2 m3 of steam.[5]
OR
Q.2(A)In an air compressor, air enters at 1.013 bar and 27C having a volume of 5 m3 and it is compressed to 12 bar isothermally. Determine (i) work done (ii) heat transfer, and (iii) change in internal energy.[5]
Q.3(A)Explain with neat sketch the construction working of Babcock and Wilcox boiler.[4]
(B) Compare: S.I.engine and C.I. engines.[3]
OR
Q.3(A) Show the function and location of the following in the boiler plant:(i) Steam stop valve (ii)Water level indicator (iii) Fusible plug (iv) Economizer.[4]
(B) Define the following terms: swept volume, clearance volume, stroke length, compression ratio.[3]
Syllabus topic:
1.Introduction:
prime movers and its types, the concept of force, pressure, Energy, work, power, System, Heat, Temperature, Specific heat capacity, Change of state, Path, Process, Cycle, Enthalpy, Statements of Zeroth law and First law.
2. Properties of gases:
Gas laws, Boyle law, Charles's law. combined gas law, Gas constant, Relation between cp and cv, Various non-flow processes like constant volume process, constant pressure process, Isothermal process, Adiabatic process, Polytropic process.
3. Properties of steam:
steam formation, types of steam, Enthalpy, Specific volume, Internal Energy and dryness fraction of steam, use of steam tables.
4. Internal combustion Engines:
Introduction , Classification , Engine details,Four-stroke / Two-stroke cycle petrol / Diesel Engines.