GATE ME 2021 : Thermodynamics & Applications Quiz 4 (App update required to attempt this test)

According to second law of thermodynamics, the entropy change of the system for any process can be

A cyclic device operates between three thermal reservoirs, as shown in the figure. Interactions between the cyclic device and the respective thermal reservoirs  are shown in the figure and  all are in the form of heat transfer. The cyclic device can be _____.

2 kg of air initially at 7 bar pressure and 400 K expands polytropically (PV^1.2 = Constant) until the pressure is reduced to one-fifth value.The change in entropy (in kJ/K )  is _____. (Take R= 0.287 kJ/kgK and γ=1.4)

Air is flowing steadily through a thermally insulated duct. The pressure and temperature of the air measured at two different stations are as follows:

Considering air as an ideal gas, the direction of flow of air in the duct is ____.

A 100 kg block of iron casting at 500 K is thrown into a large lake that is at a temperature of 285 K. The iron block eventually reaches thermal equilibrium with the lake water. Assuming on average specific heat of 0.45 kJ/kgK for the iron, the entropy generated during the process is ______ kJ/K.