Thermodynamics Questions and Answers

An ideal gas undergoes a process in which its pressure P and volume V obey P V constant Bulk modulus of gas in the process is 1 P 2 Px P X 4 x p Volume pressure and temperature of an ideal gas aro K P and I respectively If mass of its 3

A constant volume gas thermometer shows pressure reading of 50 cm and 90 cm of mercury at 0 C and 100 C respectively When the pressure reading is 60 cm of mercury the temperature is 25 C 40 C 15 C 12 5 C

34 A thermoflask made of stainless steel contains serveral tiny lead shots If flask is quickly shaken up and down several times the temperature of lead shots a Increase b Decrease c Remains same d First increase then doo

a a 4 P V 3V V c 6 P V d 15 P Vo 0 19 For the process as shown below the heat supplied to the system is 30 kJ per cycle The efficiency of the cycle is P kPa a 40 8 2 O b 12 Po Vo 0 A 2 b 60 6 B C V m c 50 d 30

36 A carnot engine working between 300 K and 600 K has work output of 800 J sec The amount of heat energy supplied from the source of engine in each cycle is a 1600 J b 1750 J c 1609 J d 1681 J 7 A carnot engine

35 A carnot engine extract heat from water at 0 C and rejects it to room at 24 4 C The work required by the refrigerator for every 1 kg of water converted into ice L 336 kJ kg ice a 20 kJ c 19 kJ b 25 kJ d 30 kJ

V 19 For a certain mass of gas the isothermal curves between P 2 303 RT log and V at T and T temperatures are 1 and 2 as shown in figure then a T T T T b T T OT P P 2 T 2 T

d 0 028 x 106 If Qaf 80 cal W 60 cal and W 30 cal for the iaf curved path f i then value of Q for path f i will be PA a 50 cal 18 The P Y 1 a b 30 cal V c 30 cal d 50 cal

14 If Q E and W denote respectively the heat added change in internal energy and the work done in a closed cyclic process then which of these will follow 0 b AQ 0

One mole of ideal monoatomic gas at initial state a with pressure P and v is taken to a final state d with pressure through the path a b c d figure a b and c d are adiacbatic paths where as b c is isothermal with temperature To Find the work done by the gas in the process b c Given In e 1 e p and volume P d e Po Vole O 2RT ORT 4RT Po Vo V La

336 W Power t 60 Two liquids A and B are at 32 C and 24 C When mixed in equal masses the temperature of the mixture is found to be 28 C Their specific heats are in the ratio of 1 3 2 2 2 3 3 1 1 4 4 3

Q 1 In different experiments an ideal gas is expanded through i Isothermal ii Adiabatic iii Isobaric process 65 In which of the processes mentioned the internal energy of the gas may decrease

2 x 10 P Pa 1 x 10 D B C T 1 414 R The net work done on the gas in the cycle ABCDA is 2 276 R Foro 300 k Assume the gas to be ideal the work done on the gas in taking it from A to B is 1 200 R 2 300 R 3 400 R 4 500 R The work done on the gas in taking it from D to A is 2 414 R 500 k 3 690 R 3 1076 R 4 690 R 4 1904 R 2X107

A black body is at a temperature of 5760 K The energy of radiation emitted by the body at wavelength 250 nm is U at wavelength 500 nm is U and that at 1000 nm is U3 Wien s constant b 2 88 x 106 nmk Which of the following is correct Question Type Single Correct Type 1 U 0 2 U3 0

Figure shows a cylinder containing helium gas at atmospheric pressure with a lightly fitting piston of weight one fourth the force acting due to atmospheric pressure The cylinder is jammed at its bottom A block B is hung by means of a mass less string whose other end is attached to the piston It is observed that the piston just starts sliding next the block B is directly placed above the piston Assuming the piston to move slowly find the fractional volume of the gas compressed 3 fixed A B C 1 D B

j A manufacturer claims to have constructed an engine tha has an efficiency of 35 when operated between th Boiling point of water and the freezing point of water Is hi claim correct Justify your answer with calculations