26. Specific heat of air at constant pressure is equal to
(a) 0.17
(b) 0.21
(c) 0.24
(d) 1.0
(e) 1.41
Ans: c
27. Characteristic gas constant of a gas is equal to
(a) C/Cv
(b) Cv/Cp
(c) Cp – Cv
(d) Cp + Cv
(e) Cp x Cv
Ans: c
28. The behaviour of gases can be fully determined by
(a) 1 law
(b) 2 laws
(c) 3 laws
(d) 4 laws
Ans: d
29. The ratio of two specific heats of air is equal to
(a) 0.17
(b) 0.24
(c) 0.1
(d) 1.41
(e) 2.71
Ans: d
30. Boyle’s law i.e. pV = constant is applicable to gases under
(a) all ranges of pressures
(b) only small range of pressures
(c) high range of pressures
(d) steady change of pressures
(e) atmospheric conditions
Ans: b
31. Which law states that the internal energy of a gas is a function of temperature
(a) Charles’ law
(b) Joule’s law
(c) Regnault’s law
(d) Boyle’s law
(e) there is no such law
Ans: b
32. The same volume of all gases would represent their
(a) densities
(b) specific weights
(c) molecular weights
(d) gas characteristic constants
(e) specific gravities
Ans: c
33. Which law states that the specific heat of a gas remains constant at all temperatures and pressures
(a) Charles’ Law
(b) Joule’s Law
(c) Regnault’s Law
(d) Boyle’s Law
(e) there is no such law
Ans: c
34. An open system is one in which
(a) mass does not cross boundaries of the system, though energy may do so
(b) neither mass nor energy crosses the boundaries of the system
(c) both energy and mass cross the boundaries of the system
(d) mass crosses the boundary but not the energy
(e) thermodynamic reactions do not occur
Ans: c
35. According to which law, all perfect gases change in volume by l/273th of their original volume at 0°C for every 1°C change in temperature when pressure remains constant
(a) Joule’s law
(b) Boyle’s law
(c) Regnault’s law
(d) Gay-Lussac law
(e) Charles’ law
Ans: e
36. Gases have
(a) only one value of specific heat
(b) two values of specific heat
(c) three values of specific heat
(d) no value of specific heat
(e) under some conditions one value and sometimes two values of specific heat
Ans: b
37. According to Avogadro Hypothesis
(a) the molecular weights of all the perfect gases occupy the same volume under same conditions of pressure and temperature
(b) the sum of partial pressure of mixture of two gases is sum of the two
(c) product of the gas constant and the molecular weight of an ideal gas is constant
(d) gases have two values of specific heat
(e) all systems can be regarded as closed systems
Ans: a
38. Extensive property of a system is one whose value
(a) depends on the mass of the system like volume
(b) does not depend on the mass of the system, like temperature, pressure, etc.
(c) is not dependent on the path followed but on the state
(d) is dependent on the path followed and not on the state
(e) is always constant
Ans: a
39. Work done in a free expansion process is
(a) + ve
(b) -ve
(c) zero
(d) maximum
(e) minimum
Ans: c
40. The statement that molecular weights of all gases occupy the same volume is known as
(a) Avogadro’s hypothesis
(b) Dalton’s law
(c) Gas law
(d) Law of thermodynamics
(e) Joule’s law
Ans: a
41. To convert volumetric analysis to gravimeter analysis, the relative volume of each constituent of the flue gases is
(a) divided by its molecular weight
(b) multiplied by its molecular weight
(c) multiplied by its density
(d) multiplied by its specific weight
(e) divided by its specific weight
Ans: b
42. If a gas is heated against a pressure, keeping the volume constant, then work done will be equal to
(a) + v
(b) – ve
(c) zero
(d) pressure x volume
(e) any where between zero and infinity
Ans: c
43. An isolated system is one in which
(a) mass does not cross boundaries of the system, though energy may do so
(b) neither mass nor energy crosses the boundaries of the system
(c) both energy and mass cross the boundaries of the system
(d) mass crosses the boundary but not the energy
(e) thermodynamic reactions do not occur
Ans: b
44. Properties of substances like pressure, temperature and density, in thermodynamic coordinates are
(a) path functions
(b) point functions
(c) cyclic functions
(d) real functions
(e) thermodynamic functions
Ans: b
45. Which of the following quantities is not the property of the system
(a) pressure
(b) temperature
(c) specific volume
(d) heat
(e) density
Ans: d
46. According to Avogadro’s law, for a given pressure and temperature, each molecule of a gas
(a) occupies volume proportional to its molecular weight
(b) occupies volume proportional to its specific weight
(c) occupies volume inversely proportional to its molecular weight
(d) occupies volume inversely proportional to its specific weight
(e) occupies same volume
Ans: e
47. Mixture of ice and water form a
(a) closed system
(b) open system
(c) isolated system
(d) heterogeneous system
(e) thermodynamic system
Ans: d
48. Which of the following is the property of a system
(a) pressure and temperature
(b) internal energy
(c) volume and density
(d) enthalpy and entropy
(e) all of the above
Ans: e
49. On weight basis, air contains following parts of oxygen
(a) 21
(b) 23
(c) 25
(d) 73
(e) 79
Ans: b
50. Which of the following is not the intensive property
(a) pressure
(b) temperature
(c) density
(d) heat
(e) specific volume
Ans: d