(aj Describe the fixed voltage Wheatstone bridge method of strain measurements. How calibration
can be done on strain gauge circuits.

(b) Four 600 Q strain gauges are connected to each arm of a Wheatstone bridge. Each gauge has a
grid area of 50 mm’. Calculate the permissible gauge current Ig, voltage ५ and bridge
sensitivity when the power density is Pd — 0.0004 W/mm?. (3)

(a) Obtain the sensitivity of constant current potentiometer circuitry for strain measurement. (3) (b)

Explain about any one dynamic recording device. (4)

(c) Describe the stress-optic law. (2)
PART C

(a) Describe the use ofisostatics and isoentatics in brittle coating test? (4)

(b) Explain about magnetic particle inspection. Mention its merits and demerits. (8)

(a) Which are the steps in brittle coating test? (4)

(b) Discuss about the failure theories ofbrittle coating. (6)
(c) Name the variables influencing the accuracy of brittle coating application. (2)

(a) How defect detection can be achieved by liquid penetrant test, discuss in detail? (5)

(b) What are ultrasonic waves and how they are classified? With suitable figures describe
about ultrasonic flaw detection technique. (7)