Determine the correctness or otherwise of the following Assertion (a) and Reason (r).
Assertion (a): Peak aging time for an Al-4 wt.% Cu alloy is indicated by a maximum in the hardness.
Reason (r): The maximum volume fraction of the θ precipitates is formed at the peak aging time.
A. a is true but r is false
B. a is false but r is true
C. both a and r are true, and r is the reason for
D. both a and r are true, but r is not the reason for a
Answer: Option A
A plastically deformed metal crystal at low temperature exhibits wavy slip line pattern due to
A. Dislocation pile-up
B. Large number of slip systems
C. Low stacking faultenergy
D. Dislocation climb
Which of the following microstructures of the eutectic is not observed in binary alloys?
A. Lamellar
B. Widmanstatten
C. Acicular
D. Nodular
Upon addition of sodium oxide to molten silicate slag, the viscosity of the slag
A. decreases because the oxygen ions supplied by the sodium oxide break the chain structure of the silicate slag
B. increases because the oxygen ion supplied by the sodium oxide further add to the oxygen network in the slag
C. remains unaffected because fundamentally one can not distinguish between the oxygen ions supplied by the sodium oxide and those already present in the slag
D. remains unaffected because the oxygen ions fill up the holes and vacancies present in the liquid slag
A. P-4, Q-3, R-2, S-1
B. P-1, Q-2, R-3, S-4
C. P-2, Q-4, R-1, S-3
D. P-2, Q-4, R-3, S-1
Join The Discussion