Heat & thermodynamics CH #11

Multiple Choice Questions

(i) The sum of all the kinetic energies of all the molecules in a substance is known as:(a) Temperature (b) heat (c) potential energy (d) momentum

(ii) The size of the molecules is much ________ than the separation between molecules:(a) larger (b) smaller (c) equal (d) zero

(iii) The pressure exerted by the gas is directly proportional to the average __________ kinetic energy of the gas molecules:(a) translational (b) rotational (c) vibrational (d) all of these

(iv) For an ideal gas system by increasing internal energy, its temperature also:(a) increases (b) decreases (c) remain constant (d) all of these

(v) In which of the following process no heat enters or leaves the system :(a) Adiabatic (b) isothermal (c) reversible (d) irreversible

(vi) The efficiency of diesel engine is:(a) 25% to 30% (b) 25% to 40% (c) 35% to 30% (d) 30% to 40%

(vii) A succession of events which bring the system back to its initial condition is called:(a) loop (b) backward process (c) cycle (d) node

(viii) Explosion is the example of which process:(a) adiabatic (b) isothermal (c) reversible (d) irreversible

(ix) The unit of thermodynamic scale is:(a) Kelvin (b) joule (c) centigrade (d) watt

10) In which process maximum work done is possible:(a) Isothermal (b) Adiabatic (c) Isochoric (d) Isobaric

11) In adiabatic expansion, the internal energy of the gas : (a) Increases (b) Decreases (c) Becomes zero (d) Remains same

12) Boyle’s law holds good for which process:(a) Isothermal (b) Adiabatic (c) Isochoric (d) Isobaric

13) Value of Boltzmann constant ‘k’ is equal to:(a) 1.38×10−23 J K−1 (b) 1.38×1023 J K−1 (c) 1.38×10−13J K−1 (d)

1.38×1013 J K−1

14) Boltzmann constant ‘k’ is equal to:

(a)N A

R(b) RN A (c)

RN A

(d) None of these

15) The efficiency of a Carnot engine is given by:

(a)T2

T1

−1 (b) T1

T2

−1 (c) 1−T 2

T 1

(d) 1−T 1

T 2

16) The difference between molar specific het at constant pressure and at constant volume is called:(a) Heat capacity (b) Molar specific heat (c) Gas constant (d) All of these

17) K.E of gas molecule is:

(a) RT (b) 23kT (c)

32kT (d)

23RT

18) PV γis equal to:(a) RT (b) nRT (c) nkT (d) Constant

19) Change in temperature of a body is 500C. The change in temperature on the Kelvin scale is:(a) 50K (b) 100 K (c) 273 K (d) 373 K

20) If heat energy is removed from an object, it temperature will normally :(b) Rise (b) Falls (c) Falls then Rise (d) Remains same

21) In Isothermal process, change in internal energy is:

Heat & thermodynamics CH #11

(a) Zero (b) Maximum (c) Minimum (d) None22) Normal human body temperature is:

(a) 350C (b) 360C (c) 370C (d) 380C23) Metabolism is the name of a process in which energy transformation takes place within:

(a) Heat engine (b) Human body (c) Atmosphere (d) All of these

24) Which one is not an example of adiabatic process:(a) rapid escape of air from a burst tyre (b) rapid expansion of air (c) cloud formation in the atmosphere (d) conversion of water into ice in

refrigerator25) Which one of the following is correct relation:

(a) Cp+Cv=γ (b) γ= Cp / Cv (c) Cp=1+R/Cv (d) Cp=1-R/Cv

26) For a gas obeying Boyles law if the pressure is doubled the volume becomes:(a) double (b) four times (c) one half (d) one fourth

27) Triple point of water is:(a) 2730C (b) 3730C (c) 273.160C (d) 373.160C

28) Which quantity is a state function:(a) internal energy (b) heat supply (c) pressure (d) volume

29) The unit of entropy is:(a) Nm/sec (b) J.K (c) J/K (d) all of these

30) Which of the following is unit of pressure:(a) Kgm-2s (b) kgm-1s (c) kgms-2 (d) kgm-1s-2

31) Which of the following is not an irreversible process:(a) Explosion (b) slow compression of gas (c) Dissipation of energy (d) Friction

32) Theoretically volume of the ideal gas becomes zero at :(a) 273.16 K (b) -273.16 K (c) -273 K (d) 0 K

33) Thermal pollution is an inevitable consequence of which law:(a) 1st law of thermodynamics (b) 2nd law of thermodynamics(c) 3rd law of thermodynamics (d) all of these

34) Heat naturally flows:(a) From low to high temperature (b) From high to low temperature(c) at uniform rate (d) at high rate

35) The process in which work is done at the expense of internal energy is called:(a) Isothermal process (b) irreversible process (c) reversible process (d) adiabatic process