BE (2nd Semester)
Basic Mechanical Engineering
1. (a) Define work and heat.
(b) Show that work is a path function.
(c) A piston and cylinder machine contains a fluid system which passes a complete cycle of four processes. During a cycle, the sum of all heat fers is 170 kJ. The system, completes 100 cycles per min. Complete following table.
Process Q (kJ/min) W (kJ/min) (kJ/min)
a-b 0 2,170 ?
b-c 21,000 0 ?
c-d -2,100 ? 36,600
d-a ? ? ?
2. (a) Define entropy.
(b)Show that entropy is a point function.
(c) Show that = notto= 1- 1/r kr-1
3. (a) What is Dryness fraction ?
(b) A vessel of volume 0.04 m3 contains a mixture of saturated water and rated steam at a temperature of 250?C. The mass of the liquid present is Find the pressure, the mass, the specific volume, the enthalpy, the and internal energy.
(c) What is Blow-of-cock ? Describe it with neat sketch.
4. (a) Define Welding.
(b) What is oxy acetylene gas welding? Describe different types of oxy- acetylene welding flaming.
(c) What are the classifications of Lathe? Describe engine lathe.
5. (a) Define Stress and Strain.
(b) Show stress and strain diagram for ductile and brittle material.
where K is Bulk modulus, E is Young’s modulus of elasticity is 1/m Poisson’s ratio.