Punjab Technical University 2010-1st Sem B.Tech Elements of Mechanical Engineering, B Tech ester, Regular , , - Question Paper

Time: three Hours
Maximum Marks: 60

Instruction to Candidates:
1) Section- A is Compulsory.
2) Attempt any 5 ques. from Section- B & C
3) choose at lowest 2 ques. from part - B & C

part – A [Marks 2*10=20]

Q1)a) How is the property of system classified?

b) What do we understand by energy in Transit?

c) Differentiate ranging from the adiabatic and polytropic process.

d) Why C is greater than Cp?

e) elaborate the assumptions for steady flow process?

f) Sketch the Carnot cycle on p-V and TS diagram.

g) describe the effective pressure for Reciprocating engine,

h) State the legal regulations of lifting of machine.

i) What is kinematic link.

j) Sketch a Stress-Strain of ductile and brittle materials and show the salient point on it.

part - B [Marks : eight Each]

Q2) (a) describe and discuss the Zeroth legal regulations of thermodynamics. Why is it so called?


(b) A non flow reversible process occurs for which pressure and quantity are correlated by the expression PV=150,w here V is the quantity in m3 and is the pressure in bar. Make computations for the work done on or by the system as pressure increase from 10 bar to 100 bar indicate the nature of process heat her expansion or compression.

Q3) (a) How are the state parameter P, V and T related in a polytropic process? elaborate the values of polytropic exponent for isochoric isothermal and adiabatic process.

(b) Show that the internal energy is a property of the system.

Q4) The gas leaving the turbine jet engine flows steadily into the Jet pipe with enthalpy9 60 kJ/kg and velocity 250m/s relate to the pipe. Thee exit from the pipe is at enthalpy and the exhausts in line with intake. Neglecting from the system determine the relative velocity of gas leaving the pipe.

Q5) discuss the establishment of thermodynamic temperature scale. Why is thermodynamic temperature scale called the absolute temperature scale.

part - C [Marks : eight Each]

Q6) Derive an expression or the air standard efficiency and mean effective pressure of an Otto cycle. State the assumptions.

Q7) (a) explain briefly the working of a four stroke diesel engine.

(b) Make a tagged sketch of Oldham coupling?

Q8) explain the different inversion of doubles lidercrank chain mechanism.

Q9) An unknown weight falls four cm on to a collar rigidly attached to the lower end of a vertical bar4 m long and eight cm sectional of the maximum instantaneous extension is obtained to be 0.42 cm. obtain the corresponding stress and the value of unknown weight E = 200 kN/mm2.

Earning:   Approval pending.