JNTU IV B.Tech I Semester Supplimentary Examinations, February 2008
(Metallurgy & Material Technology)
1. (a) What is the frequency (per second) and energy per quantum (in joules) of x-ray beams of wavelength 0.71A0 (Mo K? ) and 1.54A0 (Cu K? )?
(b) Calculate the velocity and kinetic energy with which the electrons strike the target of an X-ray tube operating at a voltage ‘V’. Determine the short wavelength limit of the continuous spectrum emitted and the maximum energy per quantum of radiation?
2. (a) Explain the phenomenon ‘scattering by a unit cell’ with neat sketch.
(b) Structure factor is independent of the shape and size of the unit cell. Explain.
3. (a) Describe Laue method of X-ray diffraction.
(b) What does the each intense point in X-ray diffraction represent in Laue pattern? Explain.
4. (a) How does Debye-Scherrer diffraction pattern look?
(b) Where is Debye-Scherrer method useful?
(c) Explain how a powder camera is superior to a Diffractometer with examples.
5. Compare the following:
(a) Powder method and Laue method
(b) Debye-Scherrer Camera and Guinier Camera.
6. (a) Cu K? radiation is incident on a Xenon filled proportional counter. Calculate the ratio of average pulse size in the escape peak to that in the normal peak.
(b) Write a note on energy-intensive Diffractometry.
7. What is the basic principle involved in crystal structure determination? Explain various steps involved in determination of unknown structures.
8. Write notes on the following:
(a) Focussing Cameras
(b) Techniques used in stress measurements.