V1 to V2 for a gas which obeys Vander Waal’s equation (V-βn)[P+(αn2/V)]=nRT (a) nRT loge [ (V2-nβ)/( V1-nβ) ]+αn2[(V1 – V2)/(V1 V2)] (b) nRT log10 [ (V2-nβ)/( V1-nβ) ]+αn2[(V1 – V2)/(V1 V2)] (c) nRT loge [ (V2-nα)/( V1-nα) ]+βn2[(V1 – V2)/(V1 V2)] (d) …
V1 to V2 and then compressed to original volume V1 adiabatically. Initial pressure is P1 and final pressure is P3 . The total work done is W. Then (a) P3 > P1 ,W > 0 …
(a) 4 RT (b) 15 RT (c) 9 RT (d) 11 RT Answer-d (3)
(a) (2/3)Q (b) (3/5)Q (c) (2/5) Q (d)(1/5)Q Ans. c (9)
at 00C and also contains an insulated piston of negligible weight and negligible thickness at the middle point. The gas on one side of the piston is heated to 1000c. If the piston moves 5cm the length of the hollow …
T1, is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature. T2 by releasing the piston suddenly. If L1 and L2 are the lengths of the gas column before and …
The mass of the gas in A is mB and that in B is . The gas in each cylinder is now allowed to expand isothermally to the same final volume 2V. The changes in the pressure in A and …
(a) Transfer of heat by radiation (b) Electrical heating of a nichrome wire (c) Transfer of heat by conduction (d) Isothermal compression Ans. d (16)
(a) Positive work is done by ice-water system on the atmosphere (b) Positive work is done on the ice-water system by the atmosphere (c) The internal energy of the ice-water system increases (d) The internal energy of the ice-water system …
volume of 1671 cm3 .If the atmospheric pressure = 1.013 x 105 N/m3 and the mechanical equivalent of heat = 4.19 J/calorie , the energy spent in this process in overcoming intermolecular forces is (a) 540 cal (b) 40 cal …
between 227°C and 127°C. It absorbs 6 x 104 cals of heat at higher temperature. Amount of heat converted to work is (a) 2.4 x 104 cal (b) 6 x 104 cal (c) 6 x …
at temperature 727°C and 227°C. The maximum possible efficiency of such an engine is (a) 1/2 (b) 1/4 (c) 3/4 (d) 1 Ans. a (13)
of – 23°C and the compressed gas in the condenser has a temperature of 27°C. The theoretical coefficient of performance is (a) 5 (b) 8 (c) 6 (d) 6.5 Ans. a (21)
-130c . The coefficient of performance of the engine is 5. The temperature of the air (to which heat is rejected) will be (a) 325°C (b) 325K (c) 39°C (d) 320°C Ans. c (15)
T1 and T2 has an efficiency η, the new efficiency if both the source and sink temperature are doubled, will be (a) η/2 (b) η …
(a) 100 J (b) 300 J (c) 500 J (d) 700 J Answer-c (14)
(a) 227°C (b) 327°C (c) 127°C (d) 27°C Answer-c (192)
T1 and sink temperature is T2 will be (a) (T1 – T2)/ T1 (b) (T2 –T1 )/T2 (c) (T1 – T2)/ T2 …
(a) 80 K, 60 K (b) 100 K, 80 K (c) 60 K, 40 K (d) 40 K, 20 K Answer-d (12)
(a) Isothermal expansion (b) Adiabatic expansion (c) Isothermal compression (d) Adiabatic compression Answer-a (22)
3×106 cal. of heat from a reservoir at 627°C, and gives it to a sink at 27°C. The work done by the engine is (a) 4.2×106 J …
(a) Second law of thermodynamics (b) Conservation of momentum (c) Conservation of mass (d) First law of thermodynamics Answer-a (9)
(a) Prevent radiation (b) Find ideal sources (c) Reach absolute zero temperature (d) Eliminate friction Answer-c (7)
(a) 200 K (b) 400 K (c) 600 K (d) 800 K Answer-b (7)
(a) 1.73 : 1 (b) 1 : 1.73 (c) 1 : 1 (d) 1 : 2 Answer-b (6)
(a) It is impossible (b) It is possible but less probable (c) It is quite probable (d) Data are incomplete Answer-a (7)
(a) 1000 K (b) 960 K (c) 846 K (d) 754 K Answer-b (6)
(a) Isobaric (b) Isotropy (c) Enthalpy (d) Entropy Answer-d (9)
(a) 1/3 (b) 2/5 (c) 3/4 …
(a) 50% (b) 24% (c) 0.75% (d) 0.4% Answer-a (2)
T2=0°C and T1=200°C its efficiency is η1 and when T1=0°C and T2=200°C , Its efficiency is η2 , then what is η1 / η2 (a) 0.577 (b) 0.733 (c) 0.638 …
(a) 300 K (b) 400 K (c) 500 K (d) 700 K Answer-a (3)
(a) Q / 4 (b) Q / 3 (c) Q / 2 (d) 2Q / 3 Answer-b (2)
(a) Isothermal (b) Adiabatic (c) Isobaric (d) None of these Ans. a (13)
27°C has a movable piston which maintains at constant pressure in container of 1 atm. The gas is compressed until temperature becomes 127°C. The work done is (Cp for gas is 7.03 cal/mol–K) (a) 703 J …
(a) T2 =273K (b) T2 =0 K (c) T1 =273K (d) T1 =0 K Answer-b (5)
(a) 127°C (b) 227°C (c) 327°C (d) 673°C Answer-b (6)
6 × 104 J at high temperature. The amount of heat converted into work is …. (a) 4.8 × 104 J (b) 3.5 × 104 J (c) 1.6 × 104 J (d) 1.2 × 104 J Answer-d (3)
(a) Zero (b) Equal to heat given to the system (c) More than the heat given to system (d) Independent of heat given to the system Answer-b (12)