ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2020

Find the particular solution for the initial value problem $$2 \sin(y^2) dx + xy \cos(y^2)dy = 0$$, if $$y(2) = \sqrt{ \left(\frac{\pi}{2}\right)}$$

When the air is passed through an insulated chamber having sprays of water maintained at a temperature higher than the dew point temperature of entering air but lower than the dry bulb temperature, then the air is said to be

In an ideal vapour compression refrigeration cycle, the specific enthalpy of refrigerant in kJ/kg at the following states is given as
Inlet of condenser : 283
Exit of condenser : 116
Exit of evaporator : 232
The COP of the cycle is

A 10 kg solid at $$100^\circ C$$ with a specific heat of $$0.8 kJ/kg^\circ C$$ is immersedin 40 kg of $$20^\circ C$$ liquid with a specific heat of $$4.0 kJ/kg^\circ C$$ The temperature of the solid after a long time if the container is insulated will be

In a counter flow heat exchanger,cold fluid enters at $$30^\circ C$$ andleaves at $$50^\circ C$$, whereas the hot fluid enters at $$150^\circ C$$ and leaves at $$130^\circ C$$. The mean temperature difference for this case is

Find the change in height (h) in a circular tube (of radius R = 1 mm) filled with liquid (water) with surface tension T = 0.073 N/m. Contact angle of water-air-glass interface is $$0^\circ$$

Oil at $$20^\circ C$$ (density = 870 kg/m^3 and viscosity = 0.104 kg/m-s) flows (laminar flo w) at 1.1 m^3/hr through a horizontal pipe with diameter d = 2 cm and length L = 12 m. Find the power required to cause the flow

A liquid of specific weight $$(pg) = 9000 N/m^3$$ flows by gravity from a tank of 0.3 m height through a 1.2 mm diameter capillary tube at a rate of 0.004 $$m^3/hr$$. as shown in figure. Sections 1 and 2 are at atmospheric pressure. Neglecting entrance effects and friction in the large tank, compute the viscosity of the liquid. Assume kinetic energy correction factor $$\alpha = 2.0.$$

An electric cable of Aluminum conductor of thermal conductivity 240 W/mK is to be insulated with rubber of thermal conductivity 0.15 W/mK. The cable is to be located in air of heat transfer coefficient of $$6 W/m^2K$$. The critical thickness of insulation will be

The power per tonne of refrigeration (in kW) is