Thermodynamics Questions and Answers

Find the temperature at which the pressure attained by the ideal gas is minimum in the process given by the equation a T To V where To and a 2 are positive constants and V is the volume of one mole of an ideal gas O O 7To 2 2To 3 3To 2

Two tangent galvanometers having coils of the same radius are connected in series A current flowing in them produces deflections of 60 and 451 respectively The ratio of the number of turns in the coils is 1 3 3 1 3 1 2 4 3 1 1 3 1

16 An electric immersion heater of 1 08 kW is immersed in water After the water has reached a temperature of 100 C how much time will be required to produce 100 g of steam a 50 s b 420 s c 105 s d 210 s tod into an

2po A Po O Di 13 VO V 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 Povo C 2V0

Equal amount of same gas in two similar cylinders A and B compressed to same final volume from same initial volume one adiabatically and another isothermally respectively then Afinal pressure in A is more than in B B C final pressure in both able equal final pressure in B is greater than in A value of y Cp is required CI D for the gas value of y

One mole of an ideal gas with heat capacity at constant pressure Cp undergoes the process T To av where To and a are constants and the volume increases from V to V the amount of heat transferred to the gas is A B C skipped D Cp R To In V2 V1 a Cp V V R To In V V1 a Cp V V RTo In V V1 R To In V V a Cp V V

For the P V diagram given for an ideal gas 1 P A P V Constant V out of the following which one correctly represents the T P diagram T 2 P 2

gas is used in carnot engine as a working If during adiabatic expansion part of the cycle the volume of gas increases from Vto 32 V the efficiency of engine is A diatomic substance 50 25 O 19 770

2 The molar heat capacity in a process of a diatomic gas if it does a work of when a heat of Q is supplied to it is 3 Correct Answer 3 Your Answer 2 Status incorrect 2552 R View In En

Problem 6 10 points Bonus Air flows adiabatically through a frictional variable area duct divergent nozzle The conditions at the inlet are M 0 2 Tt1 460K and Pt 600kPa If the ratio of the exit section to the inlet area is A A 1 4 and Pt2 333 3kPa determine the exit Mach number temperature and pressure

A gas expands from state A to state B as shown in the graph If the change in internal energy of the gas is 2 02 x 106 J find the heat flow in MJ for the gas in this process 1 atm 1 01 x 105 N m P atm 10 4 M N O 2 42 O 2 42 O 4 44 O 0 40 O 0 40 B 1 2 3 4 5 6 7 8 V m

2k V k 2 The relation between internal energy U pressure P and volume V of a gas in an adiabatic process is U a bPV where a and b are positive constants What is the value of y a a b a 1 c b d b 1 b b

8 The internal energy of an ideal gas drezorg during an isothermal process when the gas is a expanded by adding more molecules to it b expanded by adding more heat to it c expanded against zero pressure d compressed by doing work on it

d Zero 1 During an adiabatic process the pressure of a gas is found to be proportional to the cube of its temperature The ratio of Cp for the gas is 2013 C a 3 2 b 2 The molar specifio hoat c 4 3 d 5 3

Figure shows a cyclic process Heat absorbed in process A B is 100 J B A is adiabatic compression Work done on the gas in B A is 70 J Find change in internal energy in process A B 1 30 J 2 100 J P1 Question Type Single Correct Type 3 30 J B V

Calculate the amount of water that must be supplied to a heat exchanger that cools 100 kg h of tomato paste from 90 C to 20 C The tomato paste contains 40 solids The increase in water temperature should not exceed 10 C while passing through the heat exchanger There is no mixing of water and tomato paste in the heat exchanger Assume steady state Take the specific heat capacity of water to be 4187 J kg C and the specific heat capacity of the paste to be 2846 J kg C

A monoatomic ideal gas of two moles is taken through cyclic process as shown in the figure If volume V D C ratio 2 and T 27 C then AQ for the process AB will be V V 4 162B B T

Two ideal gases A and B having the same temperature T same pressur are mixed together If the temperature of mixture is kept constant and the volume occupiec the mixture is reduced to A 4P ar 9 2 B 2P then the pressure of the mixture will become C P A N Care Com

58 An ideal monoatomic gas is taken through thermodynamic states A B CD via the paths shown in the figure If UA UB Uc and Up represent the internal energy of the gas in states A B C and D respectively then which of the following is not true Pressure 2P A P A UA UD C UB UC A D Bi T C 2T Temperature B UB UA D Uc Un

33 In a thermodynamic process with 2 moles of gas 30 J of heat is released and 22J of work is done on the gas Given that initial internal energy of the sample was 20J what will be the final internal energy A 72J C 28J B 32J D 12J

A Carnot reversible engine converts 1 6 of heat input into work When the temperature of the sink is reduced by 62 K the efficiency of Carnot s cycle becomes 1 3 What is the sum of the temperature in kelvin of the source and the sink

The spectral energy distribution of star is maximum at twice temperature as that of sun Find the total energy radiated by sta One sixteenth of sun Sixteen times as that of the sun Same as that of the sun Twice as that of the sun

When a given mass of a gas is subjected to temperature changes a volume V and pressure P diagram was obtained from state 1 to state 2 During this process the gas is P O cooled continuously cooled in the beginning and heated towards the end heated in the beginning and cooled towards the end O heated continuously

Suppose that two heat engines are connected in series such that the heat released by the first engine is used as the heat absorbed by the second engine as shown in figure The efficiencies of the engines are and respectively The net efficiency of the combination is given by

20 The P T diagram for a thermodynamic process is shown in the figure The molar heat capacity of diatomic gas during this process is PA 1 2 5R 3 2R B nerAt nCVATS DV T 2 1 5R 4 3R NRT R

An event has six possible outcomes with probabilities 1 2 1 4 1 8 1 16 1 32 1 32 Find the entropy of the system CO4

One mole of a monatomic gas is involved in the cyclic process as shown in the PV graph Extension of the line segments 1 2 and 3 4 pass through the origin and the V3 if V2 2 curves 1 4 and 2 3 are isotherms Find the ratio 3 if V2 V1 PA P 2 P 1 2 13 V 5 437 Activate Windows

35 1 KW heater of capacity 1 litre is used for heating water The time required to raise the temperature of water by 10 C is specific heat of water 1 cal g C and J 4 2 Jcal A 21s C 84s B 42s D none

6 180 Consider the following PV diagram for a monoatomic gas The ratio of work done by the gas to the change in internal energy of the gas will be 2 P Q 1 3 3 1 Zero 01 1 D 2V

SolveLancer Test We are given a monoatomic gas If Cp Cy 4000 J kg K 1 find Cp SolveLancer Test a 9696 96 J kg K 1 b 6060 60 J kg K 1 c 15833 33 J kg K d 5333 33 J kg K 50a p

Objective Type Questions A sample of gas occupies 10 L under a pressure of 1 atm What will be its volume if the pressure is increased to 2 atm Assuming that temperature of the gas sample does not change 1 2 L 2 5 L 3 10 L 9

In a grand canonical ensemble a system X of fixed volume is in contact with a large reservoir Y then A X can exchange only energy with Y B X can exchange only particles with Y C X can exchange neither energy nor particles with Y D X can exchange both energy and particles with Y

8 Which of the following statements are True i Heat cannot flow from cold body to a hot body by itself ii Any engine can be more efficient than a perfectly reversible engine working between any two temperatures iii Second Law of Thermodynamics explains the direction of flow of heat energy iv Entropy always decreases Only i is True Only i ii are True Only ii iii are True O Only i iv are True

Object A and object B have equal mass Object A is at the temperature of 10C and object B is at the temperature of 80C You bring the two objects into contact After they reach thermal equilibrium the temperature is 20 C If the specific heat capacity of A is 361 g C what is the specific heat capacity of the object B Assuming no energy lose

In a Carnot engine the temperature of reservoir is 92 and that of sink is 27 C If the work done by the engine when it transfers heat from reservoir to sink is 12 6 106 J the quantity of heat absorbed by the engine from the reservoir is Kerala PET 2009 a 16 8 106 J c 7 6 106 J 18x b d 4 106 J 4 2 106 J

A closed system contains 2 kg of air at 3 bar 150 C It is stirred and expands till its pressure reduces to 1 bar During the process the temperature of the system is maintained constant at 150 C If the stirrer does 120 kJ of work determine expansion work done and ii heat transferred Assume 287 J kg K for air 4 10 har

A carnot engine having an efficiency of n 1 10 as heat engine is used as a refrigerator If the work done on the system is 10 J the amount of energy absorbed from the reservoir at lower temperature is AIEEE 2007 NEET 2017 a 99 J 1 J b 90 J d 100 J c

Problem 1 Calculate the gross and net calorific value of coal having the following compositions carbon 85 hydrogen 8 sulphur Nitrogen 2 ash 4 latent heat of steam 587 cal g

Which of the following statement is true J K CET 2006 a Internal energy of a gas depends only on the state of the gas b In an isothermal process change in internal energy is maximum c Area under pressure volume graph equals heat supplied in any process d Work done is state dependent but not path dependent A perfect gas cont in

20 Variation of internal energy with density of one mole of monoatomic gas is depicted in the adjoining figure Corresponding variation of pressure with volume can be depicted as Assuming the curve is rectangular hyperbola o 80 a c U V b P d P V V

9 An ideal gas is initially at temperature T and volume V Its volume is increased by AV due to an increase in temperature AT pressure remaining constant The quantity 8 AV V AT varies with temperature as FR M

3 03 A closed system contains air its mass is m 2 kg The initial state is p 0 25 MPa and T 30 C It undergoes a constant pressure process with heat addition of Q12 450 kJ Compute the final temperature T2 change in enthalpy AH12 change in thermal energy AU12 and work done W 2 Assume air to be an ideal gas with MolWt 29 kg kmol and c 0 714 kJ kg K

Pona using the data in the V 7 V 1 mix 7 The work 1W2 is a 0 0 kj V V VA 2 V xm b 22 kj 8 The temperature at state 2 is b 143 6 Co a 140 C c 138 6 kj 10 the heat transfer Q is 641 kj kg c 200 C 9 the specific enthalpy change h h is a 2733 8 kj kg b 2738 5 kj kg b 1949 kj kg x1 d 55 4 kj d 205 C c 641 kj kg c 584 7 kj kg 6 d 604 7 kj kg d 0 0 kj kg 7 11 8 9 P 400 kPa x1 0 7 LE Y 255 3 5 101 Your answer Typed answers are easier for students to read than handwritten notes

23 What will be the rms value of the alternating voltage represented by the equation V cos cot 2 cos 2oot 3 cos 3ct a 3 24 b 5 19 c 2 64 d 4 52 In an L R circuit the inductive reactance is equal to the resistance R of the circuit An 24

When we drink cold liquids our bodies must expend energy to maintain a normal body temperature of 37 oC How many liters of ice wate at 0 oC would you have to drink in order to use up 430 kcal Note 1 L 10 cm 3 0 001 m3 and mass density of water is pwater 1000 kg m3 Please show formulas thank you

A system performs work AW when an amount of heat is AQ added to the system the corresponding change in the internal energy is AU A unique function of the initial and final states irrespective of the mode of change is J K CET 2004 a AQ c AU and AQ b AW d AU AU

of volume 1m is divided into two equal compartments by a partition One of these compartments contains an ideal gas at 300 K The other compartment is vacuum The whole system is thermally isolated from its surroundings The partition is removed and the gas expands to occupy the whole volume of the container Its temperature now would be Manipal MEE 1995 MP PMT 2006 AMU PMT 2009 a 300 K b 239 K c 200 K d 100 K

A hot liquid contained in a container of negligible heat capacity loses temperature at rate 3 K min just before it begins to solidify The temperature remains constant for 30 min Find the ratio of specific heat capacity of liquid to specific latent heat of fusion is in K given that rate of losing heat is constant

eat capacity at constant pressure of a certain system is a function of temperature only and may be 41 87 C 2 093 t 100 J C expressed as where t is the temperature of the system in C The system is heated while it is maintained at a pressure of 1 atmosphere until its volume increases from 1600 cm3 to 2400 cm and its temperature increases from 0 C to 105 C i find the magnitude of the heat interaction and ii How much does the internal energy of the system increase

Express the differential form of the First Law of Thermodynamic Sq du 6W using enthalpy without using internal energy also write the derivation process I would be appreciated and give you thumbs up if the answers are correct and earnestly done