Mechanical Engineering is part of Engineering and holds 2,078 questions with answers, free to read and with no account needed.
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Answer: C. sum of the partial pressures of all
Dalton’s Law establishes the fundamental behavior of ideal gas mixtures in physics. The total pressure exerted equals the mathematical sum of individual partial pressures. Each gas contributes to the total pressure indep...
Answer: B. linear programming
Linear programming is a mathematical optimization technique used to allocate limited resources effectively. It maximizes or minimizes a linear objective function subject to several resource constraints. This analytical m...
Answer: E. none of the above
A milestone chart tracks significant project events and target completion dates. It focuses primarily on scheduling major deliverables rather than complex task dependencies. Therefore it fails to fulfill the specific fun...
Answer: B. compressed air before entering the combustion chamber is heated
In an open cycle gas turbine featuring a heat exchanger, compressed air is preheated. Exhaust gases transfer thermal energy to the compressed air before it enters the combustion chamber. Preheating the air reduces the fu...
Answer: D. porous body
Cork functions as an effective thermal insulator due to its porous cellular structure. Microscopic air pockets trapped within the cellular matrix restrict heat transfer. This specialized porous body minimizes conductive...
Answer: D. very much lower
Polished silver has a very low total emissivity compared to a theoretical black body. Highly polished metallic surfaces reflect thermal radiation rather than emitting it efficiently. Consequently, its radiant energy outp...
Answer: D. alpha iron, gamma from and delta iron
Iron changes its crystal lattice structure at specific elevated temperatures. Alpha ferrite exists at lower temperatures with a body centered cubic structure. Gamma austenite and delta iron represent other stable allotro...
Answer: A. ash
Ash is the non-combustible mineral matter remaining after complete combustion. Proximate and ultimate coal analyses both quantify this inorganic residue. Consequently, ash yields identical percentage figures in both anal...
Answer: B. is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable
Chilled or white cast iron is produced by cooling molten iron extremely rapidly to prevent graphite flake formation. This rapid chilling forces carbon to form hard iron carbide cementite, rendering the resulting material...
Answer: C. rising characteristic
A convection superheater absorbs heat from flowing flue gases rather than direct furnace radiation. As boiler load increases, flue gas mass flow rate and temperature rise faster than steam flow rate. This operational dyn...
Answer: D. annuity charging method
The annuity charging method calculates annual depreciation by treating asset cost as an invested sum. It charges compound interest annually on the diminishing book value while keeping depreciation constant. This financia...
Answer: B. coal gas
Coal gas contains high concentrations of combustible hydrogen and methane gases. High percentages of low-molecular-weight hydrocarbons yield a superior calorific energy release upon combustion. Manufactured coal gas trad...
Answer: D. annealing is needed between stages
Metal drawing operations severely cold-work wires and tubes, increasing hardness and reducing ductility. Excessive hardening prevents further reduction through subsequent dies without risking material fracture. Therefore...
Answer: A. cutting a sheet of metal through part of its length and then bending the cut portion
Lancing is defined as the sheet metal operation of cutting a sheet through part of its length and bending the portion. This simultaneous cutting and forming action creates raised tabs or louvers without producing any scr...
Answer: D. 10 mm/m
Cast iron patterns require a specific linear shrinkage allowance of approximately ten millimeters per meter. Molten metal contracts as it cools from pouring temperature down to ambient room conditions. Patternmakers over...
