NEET Physics Degree of Freedom Specific Heat Capacity and Mean Free Path MCQs Set A

Question. Mean free path of a gas molecule is
(a) inversely proportional to number of molecules per unit volume
(b) inversely proportional to diameter of the molecule
(c) directly proportional to the square root of the absolute temperature
(d) directly proportional to the molecular mass

Answer: A

Question. If the pressure in a closed vessel is reduced by drawing out some gas, the mean-free path of the molecules
(a) is increased
(b) increases or decreases according to the nature of the gas
(c) is decreased
(d) remains unchanged

Answer: A

Question. The specific heats at constant pressure is greater than that of the same gas at constant volume because
(a) at constant pressure work is done in expanding the gas
(b) at constant volume work is done in expanding the gas
(c) the molecular attraction increases more at constant pressure
(d) the molecular vibration increases more at constant pressure

Answer: A

Question. One mole of a gas occupies 22.4 lit at N.T.P. calculate the difference between two molar specific heats of the gas J = 4200 J/kcal
(a) 1.972 kcal/kmol K
(b) 4.569 kcal/kmol K
(c) 2.378 kcal/kmol K
(d) 3.028 kcal/kmol K

Answer: A

Question. As per the law of equi-partition of energy each vibrational mode gives how many degrees of freedom ?
(a) 2
(b) 3
(c) 0
(d) 1

Answer: A

Question. A fly moving in a room has ...X... degree of freedom. Here, X refers to
(a) three
(b) four
(c) two
(d) one

Answer: A

Question. The number of degrees of freedom for each atom of a monatomic gas is
(a) 3
(b) 5
(c) 6
(d) 1

Answer: A

Question. The total number of degree of freedom of a CO₂ gas molecule is
(a) 6
(b) 5
(c) 4
(d) 3

Answer: A

Question. The degree of freedom of a molecule of a triatomic gas is
(a) 6
(b) None of these
(c) 4
(d) 2

Answer: A

Question. P-V diagram of a diatomic gas is a straight line passing through origin. The molar heat capacity of the gas in the process will be
(a) 3 R
(b) 2.5 R
(c) 4 R
(d) None of these

Answer: A

Question. The number of collisions per second suffered by a molecule in a sample of hydrogen at S.T.P is:
[Mean free path = 1.38 × 10^–5 cm]
(a) 1.23 × 10¹⁰
(b) 1.1 × 10⁶
(c) 8.3 × 10¹²
(d) 10¹⁵

Answer: A

Question. How many degrees of freedom are associated with 2 grams of He at NTP ?
(a) 9.03 × 10²³
(b) 6
(c) 3.01 × 10²³
(d) 3

Answer: A

Question. If C_P and C_V denote the specific heats of nitrogen per unit mass at constant pressure and constant volume respectively, then
(a) C_P – C_V = R/28
(b) C_P – C_V = R
(c) C_P – C_V = 28R
(d) C_P – C_V = R/14

Answer: A

Question. The molar specific heat at constant pressure of an ideal gas is (9/2)R. The ratio of specific heat at constant pressure to that at constant volume is
(a) 1.28
(b) 1.44
(c) 1.82
(d) 1.58

Answer: A

Question. A cylinder rolls without slipping down an inclined plane, the number of degrees of freedom it has, is
(a) 2
(b) 3
(c) 5
(d) 1

Answer: A