Heating of an ore below its melting point in presence of excess of air is called September 6, 2025 by Admin A. Calcination B. Smelting C. Roasting D. Sublimation ✅ The correct answer is option C.
In __________ process, ions of salts react with water to produce acidity or alkalinity. September 6, 2025 by Admin A. Hydration B. Hydrolysis C. Electrolysis D. Dialysis ✅ The correct answer is option B.
An “orange peel” effect is observed September 6, 2025 by Admin A. As a defect during metal casting/ welding B. During deep drawing of metallic sheet having large grain size C. During faulty heat treatment of steel D. During extrusion of metal through a die ✅ The correct answer is option B.
During solid state sintering of powders, the following mechanism can be active. September 6, 2025 by Admin A. Evaporation and condensation B. Solid state diffusion processes C. Liquid formation in grain boundaries D. Creation of more dislocations ✅ The correct answer is option B.
Half life of a radioactive isotope corresponds to the time required for half of the __________ to decay. September 6, 2025 by Admin A. Atoms B. Neutrons C. Nucleons D. Electrons ✅ The correct answer is option A.
A material expanding freely due to heating will develop __________ stress. September 6, 2025 by Admin A. No B. Compressive C. Tensile D. Thermal ✅ The correct answer is option A.
__________ are not emitted by radioactive substances. September 6, 2025 by Admin A. Α-rays B. Β-rays C. Protons D. Positrons ✅ The correct answer is option C.
The most economical channel section for the fluid flow is the one for which the discharge is maximum for a given cross-sectional area. Vertical velocity distribution in an open channel for laminar flow can be assumed to be September 6, 2025 by Admin A. Parabolic B. Hyperbolic C. Straight line D. None of these ✅ The correct answer is option A.
In case of water (Prandtl number ≈ 6) flowing over a flat plate heated over the entire length, the thermal boundary layer thickness as compared to hydrodynamic boundary layer thickness is September 6, 2025 by Admin A. Less B. More C. Equal D. Unpredictable ✅ The correct answer is option A.
In practice, the compression ratio of compression-ignition (CI) engine ranges from September 6, 2025 by Admin A. 15 to 25 B. 5 to 10 C. 40 to 55 D. 60 to 70 ✅ The correct answer is option A.