Unconventional Machining Processes previous question papers JNTU

Unconventional Machining Processes previous question papers JNTU - 1

Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

1. (a) With the help of a neat sketch, explain how material is removed from a work
piece in ultrasonic machining process. [4+4=8]
(b) Explain the various factors affecting the material removal rate in ultrasonic
machining process. [8]

2. (a) Explain the process of Water Jet Machining with a neat sketch. [8]
(b) Compare the specific energy consumption by PAM and WJM [8]

3. How do the surfaces produced by Chemical Machining, Electro Chemical Machining
and conventional grinding compare? What are the .reasons for obtaining differences
in the surface finish? [16]

4. (a) What are the various advantages of using ECM? [8]
(b) What are the various limitations of ECM? [8]

5. Explain the various industrial applications of Electric DischargeMachining (E.D.M.)
with examples. [8+8]

6. For a relaxation circuit used in E.D.M. process prove that [16]
Vc = V0(1 - e-t/RcC) Where
Vc = Charged voltage of condenser in volts
V0 = e.m.f. Applied across the circuit for charging the condenser in volts
Rc = Charging resistance in ohms
C = Capacitance of condenser in farads
t = time in sec.

7. (a) Explain the working of solid state pulsed laser with neat sketch. [6+2]
(b) Explain the working of CO2 gas laser with neat sketch. [5+3]

8. What types of defects are observed in hydrostatic extrusion? What are the reasons
for them? What remedies are suggested by you to avoid these defects? [6+6+4]