JEE Physics Kinetic Theory MCQS Set B

Question: A container contains 32 g of O₂ at a temperature T. The pressure of the gas is P. An identical container containing 4 g of H2 at a temperature 2T has a pressure of

• a) 4P
• b) P
• c) P₁₈
• d) 8P

Answer: 4P

Question: An ideal gas is expanding such that PT = constant. The coefficient of volume expansion of the gas is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: 50 cal of heat is required to raise the temperature of 1 mole of an ideal gas from 20°C to 25°C, while the pressure of the gas is kept constant. The amount of heat required to raise the temperature of the same gas through same temperature range at constant volume is (R = 2 cal/mol/K)

• a) 40 cal
• b) 50 cal
• c) 60 cal
• d) 70 cal

Answer: 40 cal

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The energy (in eV) possessed by a neon atom at 27°C is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: If heat energy is given to an ideal gas at constant pressure, then select the graph which best represents the variation of VT with temperature (T).

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: If hydrogen gas is heated to a very high temperature, then the fraction of energy possessed by gas molecules correspond to rotational motion

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: An ideal gas undergoes a polytropic given by equation PVⁿ = constant. If molar heat capacity of gas during this process is arithmetic mean of its molar heat capacity at constant pressure and constant volume then value of n is

• a) –1
• b) +1
• c) Zero
• d) None of these

Answer: –1

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: If different ideal gases are at the same temperature, pressure and have same volume, then all gases have same

• a) Number of molecules
• b) Internal energy per mole
• c) Density
• d) Most probable speed

Answer: Number of molecules

Question: The internal energy of 10 g of nitrogen at N.T.P. is about

• a) 2025 J
• b) 2575 J
• c) 3721 J
• d) 4051 J

Answer: 2025 J

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

More Questions........................................

Question: According to C.E. van der Waal, the interatomic potential varies with the average interatomic distance (R) as

• a) R^–6
• b) R^–4
• c) R^–3
• d) R^–2

Answer: R^–6

Question:  The value of critical temperature in terms of van der Waals’ constants a and b is given by

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: To find out degree of freedom, the expression is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: A diatomic gas of molecular mass 40 g/mol is filled in a rigid container at temperature 30ºC. It is moving with velocity 200 m/s. If it is suddenly stopped, the rise in the temperature of the gas is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The ratio of average translatory kinetic energy of He gas molecules to O₂ gas molecules is

• a) 1
• b)

  

• c)

  

• d)

  

Answer: 1 

Question: Two container A and B are partly filled with water and closed. The volume of A is twice that of B and it contains half the amount of water in B. If both are at same temperature, the water vapour in the container will have pressure in the ratio of

• a) 1 : 1
• b) 2 : 1
• c) 4 : 1
• d) 1 : 2

Answer: 1 : 1

Question: At constant volume, temperature is increased then

• a) Number of collisions per unit time will increase
• b) Collision on walls will be less
• c) Collisions will be in straight lines
• d) Collisions will not change

Answer: Number of collisions per unit time will increase

Question: polyatomic gas with n degree of freedom has a mean energy per molecule given by

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: According to kinetic theory of gases, at absolute zero temperature

• a) Molecular motion stops
• b) Water freezes
• c) Liquid helium freezes
• d) Liquid hydrogen freezes

Answer: Molecular motion stops

Question: One mole of an ideal monoatomic gas requires 207 J heat to raise the temperature by 10 K when heated at constant pressure. If the same gas is heated at constant volume to raise the temperature by the same 10 K, the heat required is [Given the gas constant R = 8.3 J/mol-K]

• a) 124 J  
• b) 215.3 J
• c) 29 J
• d) 198.7 J

Answer: 124 J

Question: Relation between pressure (P) and average kinetic energy per unit volume of gas (E) is

• a)

  

• b)

  

• c)

  

• d) P = 3E

Answer:

Question: If C_s be the velocity of sound in air and C be the rms velocity, then

• a)

  

• b) C_s =C
• c) C_s< C
• d) None of these

Answer:

Question: The temperature of gas is raised from 27°C to 927°C. The rms speed is

• a) Get doubled
• b) Remain the same
• c) Gets halved
• d) None of these

Answer: Get doubled

Question: The equation of state, corresponding to 8 g of O₂ is

• a)

  

• b)

  

• c) PV = RT
• d) PV = 8RT

Answer:

Question: At 0 K, which of the following properties of a gas will be zero?

• a) Kinetic energy
• b) Potential energy
• c) Density
• d) Mass

Answer: Kinetic energy

Question: The amount of heat energy required to raise the temperature of 1 g of Helium at NTP from T₁ K to T₂ K is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: At 10^oC the value of the density of a fixed mass of an ideal gas divided by its pressure is x. At 110^oC, this ratio is

• a)

  

• b)

  

• c)

  

• d) x

Answer:

Question: The degrees of freedom of a triatomic gas is (consider moderate temperature)

• a) 6
• b) 4
• c) 2
• d) 8

Answer: 6

Question: The equation of state for 5 g of oxygen at a pressure P and temperature T, when occupying a volume V, will be (where R is the gas constant)

• a)

  

• b)

  

• c)

  

• d) PV = 5RT

Answer: