Q. A glass fibre of 5 micron diameter is subjected to a tensile stress of 20 MPa. The surface energy and elastic modulus of this material are 0.3 Jm-2 and 70 GPa, respectively. Pick the correct answer based on the information provided above: Note: The glass fibre contains a population of flaws of different lengths. […]
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Q. Determine the correctness (or otherwise) of the following Assertion [A] and the Reason [R] Assertion [A]: Refractory BCC metals like W and Mo are less ductile than FCC metals like Ni and Pt at room temperature Reason [R]: BCC metals have fewer independent slip systems than FCC metals A. Both [A] and [R] are
Q. Determine the correctness (or otherwise) of the following Assertion [A] and the Reason [R] Assertion [A]: For a material exhibiting Coble creep, a reduction in grain size results in a significant increase in creep rate Reason [R]: Grain boundaries act as a barrier to motion of dislocations A. Both [A] and [R] are true
Q. A copper-aluminium diffusion couple develops a certain concentration profile after an isothermal treatment at 600°C for 10 hours. The time required to achieve the same concentration profile at 500°C is ______________(in hours to 1 decimal place) Given: The interdiffusion coefficient for copper in aluminium at 500°C and 600°C are 4×10-14 m2s-1 and 8×10-13 m2s-1. Ans:
Q. A plate of thickness h = 120 mm is cold rolled in a mill with a roll diameter of 200 mm. If the coefficient of friction µ is 0.1, the maximum possible reduction Δh in a single pass is (in mm to one decimal place) Ans: 0.9-1.1
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Q. A vector field is given as follows: 𝑓⃗ = (−𝑥2𝑦 + 𝑥𝑦2) 𝑖̂ + (𝑥2𝑦) 𝑗 The divergence of this field evaluated at (𝑥, 𝑦) = (2, 2) is_________________ Ans: -0.1 to 0.1 .
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Q. In the A-rich end of the A-B binary eutectic phase diagram (shown below), the solidus and liquidus are straight lines The freezing range of the alloy with 16% B is___________(in oC to one decimal place) Ans: 95-105
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Q. A steel is plastically worked in the temperature range below the nose of the TTT curve and above Ms, followed by quenching to produce fine martensite. What is this process called? (A) Martempering (B) Ausforming (C) Inter-critical forming (D) Normalizing Ans: Ausforming
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Q. A long oil pipeline made of steel is suspected to have developed a scale on the inner surface due to corrosion. Which of the following non-destructive techniques is the most suitable for detecting and quantifying such a defect? (A) Dye penetrant test (B) Magnetic particle inspection (C) Ultrasonic inspection (D) Acoustic emission Ans: Ultrasonic
Q. In a Jominy end-quench test of the eutectoid plain-carbon steel, which of the following represents the sequence of microstructures observed from the quenched end of the specimen? (A) Fine Pearlite, Coarse Pearlite, Martensite and Pearlite, Martensite (B) Martensite, Martensite and Pearlite, Fine Pearlite, Coarse Pearlite (C) Coarse Pearlite, Pearlite and Martensite, Fine Pearlite, Martensite
In a Jominy end-quench test of the eutectoid plain-carbon steel, which of the Read More »
