Previous Years Thermodynamics Questions (Last Minute Revision): GATE (Mechanical)

GATE Previous years Thermodynamics questions GATE 2017 Thermodynamics solved questions set 1 By Rutuja Bothara

RUTUJA BOTHARA . Perusing B.Tech in Mechanical Engineering from Vellore Institute of Technology, Vellore. (2015-2019) Cleared JEE Mains 2015 .Cleared VITEEE-2015 with AIR 8718 . Cracked HITSEEE-2015 with AIR 91 Worked as a Career Counsellor in Teachers Academy . (2016- 2018) and BOLO app. https://unacademy.com/user/rurutujajb96-9511

The molar specific heat at constant volume of an ideal gas is equal to 2.5 times the universal gas constant (8.314 J/mol K). When the temperature increases by 100 K, the change in molar specific enthalpy is -J/mol.

mo la specific en-thal Py h

-A heat pump absorbs 10kW of heat from outside environment at 250 K while absorbing 15 kW of work. It delivers the heat to room that must be kept warm at 300K. The coefficient of Performance (COP) of the heat pump is 1.66 2.56 3.35 2.89

300 k 92 = 25 kW

Correct APPHOach Is CoP = 1.6

Wrong apProach. COP T2-T 300 300-2so Cop cop COP G No !

One kg of an ideal gas (gas constant, R 400j/kg.K; specific heat at constant volume, cv 1000j/kg.K) at 1 bar, and 300K is contained in a sealed rigid cylinder. During an adiabatic process, 100kj of work is done on the system by a stirrer. The increase in entropy of the system is J/K

Accordinq + 5*au f Thermodynamica dg_o Ad iabatic process 3 1 2. ook

The pressure ratio across a gas turbine( for air specific heat at constant pressure Cp 1040]/Kg.K and ratio of specific heats -1.4) is 10.lf the inlet temperature to the turbine is 1200K and isentropic efficiency is 0.9 the gas temperature at turbine exit is

Isenttopio efficiency is given by -12 T T2 (200 G 21 5 4-