Tiêu đề 12. THERMODYNAMICS.pdf ✅

12. THERMODYNAMICS (1.) Assuming the gas to be ideal the work done on the gas in taking it from A to B is Two moles of helium gas are taken over the cycle ABCDA , as shown in the P T− diagram[AIEEE-2009] (1) 300R (2) 400R (3) 500R (4) 200R (2.) The work done on the gas in taking it from D to A is Two moles of helium gas are taken over the cycle ABCDA , as shown in the P T− diagram[AIEEE-2009] (1) +414R (2) −690R (3) +690R (4) −414R (3.) The net work done on the gas in the cycle ABCDA is Two moles of helium gas are taken over the cycle ABCDA , as shown in the P T− diagram[AIEEE-2009] (1) 276R (2) 1076R

(4) 15.4% (8.) A Carnot engine, whose efficiency is 40% , takes in heat from a source maintained at a temperature of 500 K . It is desired to have an engine of efficiency 60% . Then, the intake temperature for the same exhaust (sink) temperature most be [AIEEE-2012] (1) 1200 K (2) 750 K (3) 600 K (4) Efficiency of Carnot engine cannot be made larger than 50% (9.) The above p v − diagram represents the thermodynamic cycle of an engine, operating with an ideal monoatomic gas. The amount of heat, extracted from the source in a single cycle is[JEE (Main)-2013] (1) 0 0 pv (2) 0 0 13 2       p v (3) 0 0 11 2       p v (4) 0 0 4p v (10.) An ideal gas enclosed in a vertical cylindrical container supports a freely moving piston of mass M . The piston and the cylinder have equal cross sectional area A . When the piston is in equilibrium, the volume of the gas is V0 and its pressure is P0 . The piston is slightly displaced from the equilibrium position and released. Assuming that the system is completely isolated from its surrounding, the piston executes a simple harmonic motion with frequency [JEE (Main)-2013] (1) 0 0 1 2   A P V M (2) 0 0 2 1 2  V MP A (3) 2 0 0 1 2   A P MV (4) 0 0 1 2  MV A P (11.) One mole of diatomic ideal gas undergoes a cyclic process ABC as shown in figure. The process BC is adiabatic. The temperatures at AB, and C are 400 K,800 K and 600 K respectively. Choose the correct statement. [JEE (Main)-2014]