List of top Engineering Sciences Questions

Which one of the following statements is FALSE?

Consider a fully adiabatic piston-cylinder arrangement as shown in the figure. The piston is massless and the cross-sectional area of the cylinder is $A$. The fluid inside the cylinder is air (considered as a perfect gas), with $\gamma$ being the ratio of the specific heat at constant pressure to the specific heat at constant volume for air. The piston is initially located at a position $L_1$. The initial pressure of the air inside the cylinder is $P_1 \gg P_0$, where $P_0$ is the atmospheric pressure. The stop $S_1$ is instantaneously removed and the piston moves to the position $L_2$, where the equilibrium pressure of air inside the cylinder is $P_2 \gg P_0$. What is the work done by the piston on the atmosphere during this process?

A cylindrical rod of length $h$ and diameter $d$ is placed inside a cubic enclosure of side length $L$. $S$ denotes the inner surface of the cube. The view-factor $F_{S-S}$ is

Consider a counter-flow heat exchanger with the inlet temperatures of two fluids (1 and 2) being $T_{1, in} = 300$ K and $T_{2, in} = 350$ K. The heat capacity rates of the two fluids are $C_1 = 1000$ W/K and $C_2 = 400$ W/K, and the effectiveness of the heat exchanger is 0.5. The actual heat transfer rate is ............... kW. (Answer in integer)

Consider incompressible laminar flow of a constant property Newtonian fluid in an isothermal circular tube. The flow is steady with fully-developed temperature and velocity profiles. The Nusselt number for this flow depends on

A heat engine extracts heat ($Q_H$) from a thermal reservoir at a temperature of 1000 K and rejects heat ($Q_L$) to a thermal reservoir at a temperature of 100 K, while producing work ($W$). Which one of the combinations of [$Q_H$, $Q_L$ and $W$] given is allowed?

Match the engineering materials at room temperature with the given crystal structures.

A cylindrical casting has 10 cm diameter and a mass of 12.56 kg. The material density is $ 7.85 \times 10^{-3} \, \text{kg/cm}^3 $. The value of exponent $n$ is 2 and solidification time is 12 min. The Chvorinov's constant, in min/cm$^2$, is ................. (round off to 2 decimal places).

A metal rod of diameter 14 mm is subjected to a tensile test. After the test, its cross-sectional diameter at the fractured end is 12 mm. The ductility, in %, is ................. (round off to 2 decimal places).

A solid circular disk of 0.025 m thickness is used as a flywheel. The density of the disk material is 7800 kg/m³ and the mass moment of inertia of the disk about its center is 4.36 kg·m². The radius, in m, of the disk is ................. (round off to 2 decimal places).

Creep of mild steel at elevated temperature involves

Assume the Earth is in radiative equilibrium with an effective radiative temperature of 255 K. If the planetary albedo increases by 0.05, then the effective radiative temperature of the planet will be _________ $\text{ K}$. (Round off to the nearest integer)

Consider a tornado in cyclostrophic balance. The tangential wind speed at a radial distance of 500 m from the center of the tornado is _________ $\text{m/s}$, if the pressure gradient at that location in the radial direction is 5 N/m^3. Assume the density of air to be 1 kg/m^3 . (Round off to the nearest integer).

In gradient wind balance, which of the following statement(s) is/are true for flow around a region of low pressure in the northern hemisphere?

Consider two weather stations A and B having the same altitude. Station B is 5 km north of Station A and is always 2 K warmer than Station A. A steady northerly wind blows at 1 m/s. The change in temperature at Station A in 2 hours is _________ \text{ K}. (Round off to one decimal place).

The Rossby number of a synoptic system with a length scale of 1000 km, characteristic velocity scale of 10 m s$^{-1}$ at a latitude where the Coriolis parameter equals $10^{-4}$ s$^{-1}$, is _________ (rounded off to two decimal places).

An unsaturated moist air parcel undergoes adiabatic ascent in the atmosphere without mixing with surrounding air. Air is so clean that there is no possibility for heterogeneous nucleation. Which one of the following plots depicts the vertical variation of water vapor pressure (shown as continuous line) and saturation water vapor pressure (shown as dotted/dashed line) of the parcel?

A fluid is in solid body rotation in a cylindrical container of radius $R$ rotating with an angular velocity $\Omega = (0, 0, \Omega)$. The circulation per unit area around a circular loop in the horizontal plane of radius $r$ ($r<R$), whose center coincides with the axis of rotation is

Consider a layer of atmosphere where temperature increases with height. If the concentration of a vertically well-mixed greenhouse gas suddenly increases in this layer, then an immediate consequence is that:

Which of the following statement(s) is/are true about northern hemisphere tropical cyclones?

Which of the following feature(s) characterize the seasonal mean flow in the upper troposphere near 200 hPa level over the Tibetan Plateau during the boreal summer?

Tropical cyclones usually do not form close to the Equator primarily because

The dry bulb temperature and relative humidity of air inside a storage chamber are 37°C and 50%, respectively. The saturation pressure of water vapour at 37°C and barometric pressure are 6.28 kPa and 101.32 kPa, respectively. The humidity ratio of air inside the chamber is _________ \text{ kg water / kg dry air}. (Round off to three decimal places.)