1. Which of the following variables controls the physical properties of a perfect gas

(a) pressure
(b) temperature
(c) volume
(d) all of the above
(e) atomic mass

Ans: d

2. Which qf the following laws is applicable for the behavior of a perfect gas

(a) Boyle’s law
(b) Charles’law
(c) Gay-Lussac law
(d) all of the above
(e) Joule’s law

Ans: d

3. The unit of temperature in S.I. units is

(a) Centigrade
(b) Celsius
(c) Fahrenheit
(d) Kelvin
(e) Rankine

Ans: d

4. The unit of mass in S.I. units is

(a) kilogram
(b) gram
(c) tonne
(d) quintal
(e) newton

Ans: a

5. The unit of time in S.I. units is

(a) second
(b) minute
(c) hour
(d) day
(e) year

Ans: a

6. The unit of length in S.I. units is

(a) meter
(b) centimeter
(c) kilometer
(d) millimeter

Ans: a

7. The unit of energy in S.I. units is

(a) watt
(b) joule
(c) joule/s
(d) joule/m
(e) joule m

Ans: b

8. According to GayLussac law for a perfect gas, the absolute pressure of given mass varies directly as

(a) temperature
(b) absolute
(c) absolute temperature, if volume is kept constant
(d) volume, if temperature is kept constant
(e) remains constant,if volume and temperature are kept constant

Ans: c

9. An ideal gas as compared to a real gas at very high pressure occupies

(a) more volume
(b) less volume
(c) same volume
(d) unpredictable behavior
(e) no such correlation

Ans: a

10. General gas equation is

(a) PV=nRT
(b) PV=mRT
(d) PV = C
(c) PV=KiRT
(e) Cp-Cv = Wj

Ans: b

11. According to Dalton’s law, the total pres sure of the mixture of gases is equal to

(a) greater of the partial pressures of all
(b) average of the partial pressures of all
(c) sum of the partial pressures of all
(d) sum of the partial pressures of all divided by average molecular weight
(e) atmospheric pressure

Ans: c

12. Which of the following can be regarded as gas so that gas laws could be applicable, within the commonly encountered temperature limits.

(a) 02, N2, steam, C02
(b) Oz, N2, water vapour
(c) S02, NH3, C02, moisture
(d) 02, N2, H2, air
(e) steam vapours, H2, C02

Ans: d

13. The unit of pressure in S.I. units is

(a) kg/cm2
(b) mm of water column
(c) pascal
(d) dynes per square cm
(e) bars

Ans: c

14. A closed system is one in which

(a) mass does not cross boundaries of the system, though energy may do so
(b) mass crosses the boundary but not the energy
(c) neither mass nor energy crosses the boundaries of the system
(d) both energy and mass cross the boundaries of the system
(e) thermodynamic reactions take place

Ans: a

15. Temperature of a gas is produced due to

(a) its heating value
(b) kinetic energy of molecules
(c) repulsion of molecules
(d) attraction of molecules
(e) surface tension of molecules

Ans: b

16. According to kinetic theory of gases, the absolute zero temperature is attained when

(a) volume of the gas is zero
(b) pressure of the gas is zero
(c) kinetic energy of the molecules is zero
(d) specific heat of gas is zero
(e) mass is zero

Ans: c

17. Kinetic theory of gases assumes that the collisions between the molecules are

(a) perfectly elastic
(b) perfectly inelastic
(c) partly elastic
(d) partly inelastic
(e) partly elastic and partly inelastic

Ans: a

18. The pressure a gas in terms of its mean kinetic energy per unit volume E is equal to

(a) E/3
(b) E/2
(c) 3E/4
(d)2E/3
(e) 5E/4

Ans: d

19. Kinetic energy of the molecules in terms of absolute temperature (T) is proportional to

(a) T
(b) j
(c) J2
(d) Vr
(e) 1/Vr

Ans: a

20. Superheated vapour behaves

(a) exactly as gas
(b) as steam
(c) as ordinary vapour
(d) approximately as a gas
(e) as average of gas and vapour

Ans: d

21. Absolute zero pressure will occur

(a) at sea level
(b) at the center of the earth
(c) when molecular momentum of the system becomes zero
(d) under vacuum conditions
(e) at a temperature of – 273 °K

Ans: c

22. No liquid can exist as liquid at

(a) – 273 °K
(b) vacuum
(c) zero pressure
(d) centre of earth
(e) in space

Ans: c

23. The unit of power in S.I. units is

(a) newton
(b) pascal
(c) erg
(d) watt
(e) joule

Ans: d

24. The condition of perfect vacuum, i.e., absolute zero pressure can be attained at

(a) a temperature of – 273.16°C
(b) a temperature of 0°C
(c) a temperature of 273 °K
(d) a negative pressure and 0°C temperature
(e) can’t be attained

Ans: a

25. Intensive 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) remains constant

Ans: b