# Heat & Thermodynamics MCQs

1.4180 joules of work raises the temperature of 1 liter water through,

a. 273K

b. 100C

c. 1oC

d. 1 F

2.A certain engine converts 20% of available heat energy into work. Then its efficiency will be:

a. 0.8

b. 0.5

c. 0.6

d. 0.2

3.A sea breeze occurs during the day when the air over the land is ——————-than the air over the sea.

a. heavier

b. hotter

c. lighter

d. cooler

4.A system in which there is a flow of mass is?

a. Equilibrium system

b. Isolated system

c. Open system

d. Closed system

5.A thermometer is used for measuring

a. Length

b. Temperature

c. Heat

d. Energy

6.Absolute zero is considered as that temperature at which:

a. All gases become liquid

b. water freezezs

c. all liquid become gases

d. none

7.According to kinectic theory of gases pressure is directly proportional to

a. <M>

b. <n>

c. <K.E>

d. <V>

8.All the change in internal energy apprear as

a. Work done

b. Temprature

c. Heat

d. Exergy

9.An ideal gas passes from one equilibrium state (P1, V1, T1, N) to another equilibrium state (2P1, 3V1, T2, N). Then

a. T1=3T2

b. T1=6T2

c. T1=T2

d. T1=T2/6

10.An ideal refrigerator has a freezer at temperature −12°C. The coefficient of performance of the engine is 5. The temperature of the air (to which the heat ejected) is

a. 37.5°C

b. 50°C

c. 40.2°C

d. 45.2°C

11.An isothermal process is governed by?

a. Boyle’s Law

b. Charles Law

c. Avougder Law

d. None of these

12.At 0K entropy change is

a. neither maximum nor minimum

b. 0

c. maximum

d. minimum

13.At constant temperature the graph between V and 1/P is

a. Hyperbola

b. A straight lime

c. A curve of any shape

d. Parabola

14.At constant temperature, if the density of the gas is increased, its pressure will:

a. Remains unchanged

b. None of these

c. Increase

d. Decrease

15.At what temperature is the Fahrenheit scale reading equal to twice that of the Celsius scale?

a. 280°C

b. 360°C

c. 160°C

d. 460°C

16.At what temprature average K.E of a gas is equal to 10.2 eV

a. 788400 K

b. 78 K

c. 78840 K

d. 7884 K

17.Boltzman constant K in terms of universal gas constant R and Avagadros number Na is gives as

a. K = nRNa

b. K = R/Na

c. K = Na/Ra

d. K = RNa

18.Boyles law held for ideal gases in

a. isobaric process

b. Isothermal process

c. Isochoric process

19.By addition or removal of weight over the piston —– is change

a. Pressure

b. Impulse

c. Momentum

d. Force

20.Carnot cycle have maximum efficacy for?

a. New engine

b. Irreversible engine

c. Petrol engine

d. Reversible engine

21.Collosions of molecules of ideal gas are

a. Elastic

b. Inelastic

c. Partially Elastic

d. None

22.Cp – Cv =

a. KT

b. R

c. RT

d. nRT

23.Degree of coldness and hotness>

a. Temperature

b. Heat

c. Energy

d. All of these

24.Energy = 10.2 ev above the lowest state of hydrogen atom at what temprature K.E be equal to energy of the excited state

a. 780 K

b. 79 K

c. 79000 K

d. 790 K

25.Entropy change depend on?

a. Heat transfer

b. Mass transfer

c. Change temperature

d. None of these

26.Entropy change of system and envirnment increases in which process

a. Isobaric Process

b. Irreversible

c. Reversible

d. Isothermal Process

27.Entropy change of system and envirnment remain constant in which process

a. Isobaric Process

b. Reversible

c. Irreversible

d. Isothermal Process

28.Entropy during reversible process is?

a. May increase or decrease

b. Remain constant

c. Decrease

d. Increase

29.Entropy of system always

a. Increase and decrease

b. Increase

c. Decrease

d. None of these

30.Farenheit degree is —- than celcius degree

a. =

b. ≠

c. <

d. >

31.First law of thermodynamics is

a. dE = dQ + dW

b. dE = dQ – dW

c. dQ = dE + dW

d. dW = dE + dQ

32.First law of thermodynamics is merely a statement of law of conservation

a. Energy

b. Linear momentum

c. Charge

d. Angular momentum

33.For a gas obeying Boyle’s law if the pressure is doubled the volume becomes

a. one half

b. double

c. one forth

d. four times

34.For a gas obeying Boyle’s law, if the pressure is reduced by one half then volume is

a. four time

b. half

c. remains constant

d. Doubled

35.Force per unit area is called

a. Pressure

b. Weight

c. Momentum

d. Energy

36.General gas equation is  ?

a. PV=nRT

b. PV=mRT

c. P=VRT

d. CP-CV=R

37.Heat enter to system is taken as

a. Infinity

b. Positve

c. Negative

d. Zero

38.Heat from the Sun reaches Earth by:

a. vaporization

b. Convection

c. Conduction

39.Heat is added to the system is?

a. Positive

b. Negative

c. Remains same

d. None of these

40.Heat is transmitted through solids by a process

a. Conduction

c. Convection

d. Diffusion

41.Heat is transmitted through solids by a process called:

a. Convection

b. Diffusion

d. Conduction

42.Helmodtz function is?

a. G=H-TS

b. F=u-Ts

c. u=k.E+p.E

d. H=u+Pv

43.Hotness or coldness of an object is represented in term of:

a. heat

b. chemical energy

c. pressure

d. Temperature

44.Ideal gas relate macroscopic paramaters of thermodynamics with

a. microscopic paramaters

b. All parameters

c. Both

d. None

45.Identify the state variables given here?

a. Q, W

b. Q, T, W

c. P, T, Q

d. P, T, U

46.If 214 J of work is done on a system and 293 J of heat is extracted then dE int

a. 79

b. 67

c. 86

d. -79

47.If a molecule will momentum mv strikes a wall and rebound then the change in  momentum is

a. mv

b. -2mv

c. 2mv

d. Zero

48.If Cp = 34.4 J /mol K and vlaue of R is 8.314 then

a. Cv = 26.1 J/ mol K

b. Cv = 20.1 J/ mol K

c. Cv = 10.1 J/ mol K

d. Cv = 120.1 J/ mol K

49.If Cv denotes molar specific heat at constant volume and? T is the change in the  Temperature, then Cv∆T gives

a. entropy

b. pressure

c. volume

d. Energy

50.if the temperature of sink decreased the efficiency of the carnot engine,

a. remains constant

b. none

c. increase

d. decrease

51.If Vf > Vi then work done is

a. Infinity

b. Negative

c. Positve

d. Zero

52.If your temprature is 310 K then in celcius it is

a. 213

b. 280

c. 373

d. 37

a. Q=ΔU+W

b. Q =W

c. W=0

d. W = -ΔU

54.In an isochoric process, we have

a. ∆U = 0

b. ∆T = 0

c. W = 0

d. Q = 0

55.In an isothermal process, the internal energy of the system:

a. increase four times

b. Remains constant

c. Decreases

d. Increases

56.In ideal gas avergae translation K.E of gas molecules is proporitonal to

a. Temprature

b. Pressure

c. Volume

d. Force

57.In molar specific heat R is?

a. Cp-Cv

b. Cv-Cp

c. Cv+Cp

d. None of these

58.In non-conservation of pressure force

a. W1 = W2

b. W1 = 0

c. W2 = 0

d. W1 ≠ W2

59.In thermodynamic potential enthalpy

a. H = U – PV

b. U = H + PV

c. U = PV

d. H = U + PV

60.In which process entropy remains constant

a. Isobaric

b. isothermal

d. isochoric

61.Normal freezing point of water in degree celcius is

a. 323◦C

b. 32◦C

c. 0◦C

d. 100◦C

62.Normal human body temperature 98.6°F corresponds to______________?

a. 92 C

b. 212 C

c. 37 C

d. 40 C

63.Numerical value of Boltzmanns constant is______________?

a. 3.18×10-31JK-1

b. 3.18×10-23JK-1

c. 1.38×10-23JK-1

d. 1.38×10-31JK-1

64.On entropy liquid is?

a. equal to gas

b. <solid

c. <gas

d. >gas

65.On heating kinetic energy of molecule

a. Increase

b. Decrease

c. Remain same

d. Both a and b

66.On heating solids expands in all

a. Direction

b. Space

c. Part

d. None

67.One degree of thermodynamics scale of temperature is called:

a. Celsius

b. farenheit

d. Kelivin

68.Origion of force between molecules is

a. Magnetic Field

b. Electromegnatism

c. Electric Field

d. Gravitational Field

69.Pressure is equally exerted in all direction

a. Kelvin Statement

b. Pascal Law

c. Boyles Law

d. Charles Law

70.Real gases strictly obey gas laws at:

a. low pressure and low temperature

b. Low pressure and high temperature

c. high pressure and low temperature

d. high pressure and high temperature

71.SI unit of heat is?

a. Joule

b. Calories

c. Kelvin

d. None of these

72.Sum of all kinds of molecular energies is called

a. Kinetic Energy

b. Potential Energy

c. Vibrational Energy

d. Internal Energy

73.T dS = Cv dT + β/k T dV is called the

a. 1st TdS equaiton

b. 2nd TdS equaiton

c. 3rd TdS equation

d. None

74.Temperature and heat are

a. Different

b. Same

c. Both

d. None

75.temperature of -273oC will be on kelvin scale as,

a. 373 K

b. 273 K

c. 0 K

d. -273 K

76.Temperature of a gas is produced due to?

a. Its heating value

b. Kinetic energy of molecule

c. Attraction of molecule

d. Repulsion of molecule

77.The amount of heat energy required to raise the temprature of the substance through 1K is

a. Specific Heat Capacity

b. Heat Capacity

c. Specific heat capacity of Volume

d. None

78.The atomic mass of oxygen is?

a. 125

b. 12

c. 15

d. 16

79.the average translational K.E per molecules of an ideal gas in terms of pressure is given as+C69

a. 2P/3No

b. 3No/2P

c. 2No/3P

d. 3P/2No

80.The behavior of gases can be fully determined by  ?

a. 2nd law

b. 3rd law

c. 4th law

d. 1st law

81.The branch of physics which deals with the production of low temprature is called

a. Mechanics

b. Low temprature physice

c. Thermodynamics

d. High temprature physics

82.The efficiency of a heat engine working between the freezing point and boiling point of water is

a. 0.125

b. 0.268

c. 0.0625

d. 0.2

83.The efficiency of a heat engine working between the freezing point and boiling point of water is

a. 0.0625

b. 0.268

c. 0.125

d. 0.2

84.The energy of molecular motion appears as

a. Heat

b. Potential energy

c. Friction

d. None of these

85.The Fahrenheit and centigrade scales agree to________________?

a. 15.5

b. 542

c. 273

d. 40

86.The first law of thermodynamic is the law of?

a. Conservation of energy

b. Conservation of mass

c. Conservation of momentum

d. None of these

87.The first TDS equation has use the function of

a. S=S(T,V)

b. S=S(P,V)

c. S=S(T,P)

d. None

88.The force exerted by piston on gas is equal and opposite to force exerted by gas

a. Newton Law

b. Pascal Law

c. Boyles Law

d. Charles Law

89.The Gibbs free energy for a system is defined as

a. H = TS

b. G = H – TS

c. G = H + TS

d. H = G – TS

90.The graph between volume and temperature in Charles’ law is

a. a straight line

b. a circle

c. a parabola

d. an ellipse

91.The heat enters into the system is?

a. Positive

b. Negative

c. Both a and b

d. None of these

92.The ideal gas law is

a. PV= NRT

b. P= NRT/m

c. V = nRT

d. PV= nRT

93.The ideal gas law is given in form of,

a. TV=nRP

b. PV=nR/T

c. PT=nRV

d. PV=nRT

94.The internal energy of an ideal gas depends on

a. Temperature

b. Pressure

c. Volume

d. enthalapy

95.The major specific heat at constant pressure of an ideal gas  is 7/2 R. The ratio of specific heat at constant pressure to at  constant volume?

a. 44385

b. 44386

c. 44382

d. 44323

96.The molecules of ideal gas have only

a. Kinetic Energy

b. Potential Energy

c. Gravitational Energy

d. none

97.The molecules of ideal gas moves

a. In one dimension

b. Randomly

c. In straigth line

d. Periodically

98.The normal human body temperature in Celcius is

a. 212oC

b. 180oC

c. 37oC

d. 32oC

99.The object which is under observation?

a. System

b. Entropy

c. Enthalpy

d. None of these

100.The point at which ice liquid water and vapour  coexist with eact other is called

a. Triple point

b. Melting Point

c. Boiling Point

d. Freezing Point

101.The point particles in ideal gas are

a. Different

b. Unequal

c. Stationary

d. Identical

102.The process in which no heat enter or leave the system is called the

a. Isobaric Process

c. Isothermal Process

d. Isochoric Process

103.The process in which the pressure remains constant is called

a. Isothermal Process

b. Isobaric Process

c. Isochoric Process

104.The process in which the temprature remains constant is called

a. Isobaric Process

b. Isothermal Process

c. Isochoric Process

105.The PV diagram of isothermal expansion process is called the

a. Isothermal

c. Isobaric

d. Isochoric

106.The rate of change of momentum is=

a. Impulse

b. Applied Force

c. Pressure

d. Weight

107.The SI unit of “C”

a. Jm -1 K -1

b. Kelven

c. Joule

d. None of these

108.The SI unit of molar specific heat capacity is

a. J K / mol

b. J / mol K

c. J mol K

d. J mol / K

109.The size of one degree of Celsius is equal to_________________?

a. 3.2 degrees of Fahrenheit scale

b. 2.12 degrees of Fahrenheit scale

c. 1.8 degrees of Fahrenheit scale

d. One degree of Fahrenheit scale

110.The specific heat of air increase with increase in?

a. Both

b. Air flow

c. Temperature

d. Pressure

111.The temperature at which all the gases become liquid is called:

a. negative 273k

b. 0 C

c. Absolute zero

d. 273 k

112.The thermodynamic process in which volume remains constant is called

a. Isobaric Process

b. Isochoric Process

d. Isothermal Process

113.The unit of entropy is________________?

a. J.K

b. J/K

c. Kgm2/sec2.K

d. N.m/sec

114.The value of γ for diatomic gas is_______________?

a. 1.67

b. 1.3

c. 2.3

d. 1.41

115.The work done in the isochoric process is________________?

a. Constant

b. variable

c. zero

d. depends on situation

a. Mechanical Waves

b. Electromagnetic waves

c. Alpha rays

d. Electrons

117.Thermometer is used to measure

a. Pressure

b. Height

c. Volume

d. Temprature

118.Total heat of substance is known as

a. Internal energy

b. Entropy

c. Enthpoly

d. None of these

119.Two system in thermal equilibrium with respect to third system is

a. 2nd law of thermodynamics

b. 3rd law of thermodynamics

c. Zero law of thermodynamics

d. 1st law of thermodynamics

120.Unit of temperature is?

a. Joule

b. Kelvin

c. Pascale

d. Columb

121.Value of triple point of water is

a. 0 K

b. 280 K

c. 273.16 K

d. 100 K

122.When a cycle tyre suddenly bursts, the air inside the tyre expands. This process is

a. isobaric

b. isochoric

d. isothermal

123.When temprature of system increaes change in internal energy is

a. Neither positive nor negative

b. Positve

c. Negative

d. Zero

124.When the cyclic process is reversible then the entropy will?

a. Remain same

b. Decrease

c. Increase

d. None of these

125.When the disorder of the state of system increases, its entropy:

a. Increases

b. remain same

c. decrease

d. become zero

126.When two objects come to common temperature, the body is said to

a. Thermal equilibrium

b. Dynamics equlibrium

c. statis  equilibrium

d. none

127.When you exercise in the morning, by considering your body as thermodynamic system,  Which of the following is true?

a. U < 0, W < 0

b. U = 0, W > 0,

c. U < 0, W > 0,

d. U > 0, W > 0

128.Which of the following is an irreversible cycle

a. Striling

b. Carnot

c. Carnot and striling both

d. None of these

129.Which of the following is not state variable?

a. Entropy

b. Internal energy

c. Work

d. Temperature

130.Which of the following is the largest unit of energy

a. Calorie

b. Joule

c. Erg

d. Electron volt

131.Which of the following properties of molecules of a gas is same for all gases at particular temperature

a. mass

b. kinetic energy

c. velocity

d. momentum

132.Which one is correct relation?

a. Cp + Cv=R

b. Cp =1+R/ Cv

c. Cp=1-R/Cv

d. γ= Cp/Cv

133.Work done in a free expansion process?

a. Maximum

b. Positive

c. Negative

d. Zero

134.Work done is independent of path in

a. Conservative Field

b. Non-conservative Field

c. Gravitational Field

d. Electrostatic Field

135.Work done on the system is?

a. Negative

b. Positive

c. Zero

d. None of these

136.Zeroth law of thermodynamic explained?

a. Thermal equilibrium

b. Electrical

c. Chemical

d. None of these