List of top Mechanical Engineering Questions

Which theory is commonly used to predict the failure of ductile materials under multiaxial stress states?
In forced convection inside a pipe, the Nusselt number for fully developed laminar flow with constant wall temperature is:
In rolling of metals, when reduction per pass is increased while all other conditions are kept constant, the required rolling force
What is the primary purpose of forecasting in production planning?
The two plates are welded by a butt joint and is subjected to tensile force P as shown in figure. The average tensile stress in the weld is
What is the main cause of irreversibility in thermodynamic processes?
A solid cylinder of diameter 100 mm and height 50 mm is forged between two frictionless flat dies to a height of 25 mm. The percentage change in diameter is
The criterion of static load carrying capacity is the permanent deformation of the parts of bearing. The limiting value of permanent deformation is
Which dimensionless number characterizes the ratio of convective to conductive heat transfer in a fluid?
For an air refrigeration cycle, COP improves when
In a concentric tube counter flow heat exchanger, hot oil enters at $102\text{ }^{\circ}\text{C}$ and leaves at $65\text{ }^{\circ}\text{C}$. Cold water at $25\text{ }^{\circ}\text{C}$ and leaves at $42\text{ }^{\circ}\text{C}$. The log mean temperature difference (LTMD) is _______}
The ratio of modulus of rigidity to modulus of elasticity for a Poisson's ratio of 1 would be
Angle of twist of a shaft of diameter 'd' is inversely proportional to
What happens to the entropy of a pure substance during a phase change at constant temperature and pressure?
In free convection, which dimensionless number represents the ratio of buoyancy forces to viscous forces?
In a Diesel cycle, the parameter that affects efficiency in addition to compression ratio is
Determine the atmospheric pressure at a location where the barometric reading is 700 mmHg and the gravitational acceleration is $g = 10 \text{ m/s}^2$. Assume the mercury density is $14000 \text{ kg/m}^3$.
Which of the following processes is an example of an isothermal process?
The control volume approach in fluid mechanics is primarily used to analyse:
Which of the following is NOT a characteristic of a transportation problem?
A solid uniform metal bar of diameter D and length L is hanging vertically from its upper end. The elongation of the bar due to self-weight is
The critical speed of a rotating shaft depends on
The truss which follows the law $n =$ _________ is known as simple truss
Consider an ideal vapour compression refrigeration cycle working on R-134a refrigerant. The COP of the cycle is 10 and the refrigeration capacity is 150 kJ/kg. The heat rejected by the refrigerant in the condenser is _______ kJ/kg.
What happens to the total potential energy of a system if the external work done by applied loads is greater than the increase in internal strain energy?