Physics-DPP-1-5.Thermometry, Thermal Expansion and Kinetic Theory of Gases

PHYSICS Topic: Thermometry, Thermal Expansion and Kinetic Theory of Gases Date: 1. The specific heat at constant pressure is greater than that of the same gas at constant volume because : (a) at constant volume work is done in expanding the gas (b) at constant pressure 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 2. The number of molecules in 1 cc of water is closed to : (a) 6´ 1023 (b) 22.4´ 1024 (c) CP 1023 3 (d) 1023 3. Two mole of argon are mixed with one mole of hydrogen then CV for the mixture is nearly : (a) 1.2 (b) 1.3 (c) 1.4 (d) 1.5 4. 22 g of CO at 270C is mixed in a container with 16 g of O at 370C. If both gasses are considered as ideal kinetic theory gasses, then 2 2 temperature of mixture is : (a) 28.50C (b) 30.50C (c) 31.50C (d) 330C 5. The ratio of speed of sound in nitrogen gas to that in Helium gas at 300 K is : (a) 2 7 (b) 1 7 (c) 3 5 (d) 6 5 6. A gas has volume V and Pressure P. The total translational kinetic energy of all molecules of gas is : (a) 3 PV only, if the gas is monoatomic (b) 3 PV only, if the gas is diatomic 2 2 (c) 3 PV in all cases (d) None 2 7. If two rods of length l and 2l having coefficient of linear expansion  and  respectively are connected end on end, the average coefficient of linear expansion of composite rod equal : (a) 3 α 2 (b) 5 α 2 (c) 5 α 3 (d) None 8. A vessel contains a mixture of 1 mole of oxygen and 2 moles of nitrogen at 300 K. The ratio of the average rotational kinetic energy per O2 molecule to that per N2 molecules is : (a) 1 : 1 (b) 1 : 2 (c) 2 : 1 (d) 8 : 7 9. If the density of a gas at NTP is 1.3 kg/m3 and velocity of sound in it is 330 m/s. The number of degrees of freedom of gas molecule is : (a) 2 (b) 3 (c) 6 (d) 5 10. The radius of a ring is R and its coefficient of linear expansion is . If the temperature of ring increases by , then its circumference will increase by : (a)  R (b)  R (c) π Rα θ 2 (d) π Rα θ 4 ***End of Paper*** PHYSICS Topic: Thermometry, Thermal Expansion and Kinetic Theory of Gases Date: Answer Key 1. (b) 2. (c) 3. (d) 4. (c) 5. (c) 6. (c ) 7. (b) 8. (a) 9. (d) 10. (b)

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