CLASS : XIth SUBJECT : PHYSICS
Date : DPP No. : 7
Topic :- KINETIC THEORY
1. The temperature at which protons in proton gas would have enough energy to overcome.
Coulomb barrier of 4.14 × 10-14𝐽 is (Boltzman constant = 1.38 × 10-23𝐽𝐾-1)
a) 2 × 109𝐾 b)109𝐾 c) 6 × 109𝐾 d)3 × 109𝐾
2. KE per unit volume is 𝐸. The pressure exerted by the gas is given by
𝐸 2𝐸 3𝐸 𝐸
a) b) c) d)
3 3 2 2
3. Two cylindrical conductors 𝐴 and 𝐵 of same metallic material have their diameters in the
ratio 1 :2 and lengths in the ratio2 :1. If the temperature difference between their ends is
same, the ratio of heat conducted respectively by 𝐴 and 𝐵 per second is
a) 1 : 2 b)1 : 4 c) 1 : 16 d)1 : 8
4. A gas is collected over the water at 25℃. The total pressure of moist gas was 735 𝑚𝑚 of
mercury. If the aqueous vapour pressure at 25℃ is 23.8 𝑚𝑚. Then the pressure of dry gas is
a) 760 𝑚𝑚 b)758.8 𝑚𝑚 c) 710.8 𝑚𝑚 d)711.2 𝑚𝑚
5. Two moles of oxygen is mixed with eight moles of helium. The effective specific heat
of the mixture at constant volume is
a) 1.3 𝑅 b) 1.4 𝑅 c) 1.7 𝑅 d) 1.9 𝑅
6. Mean kinetic energy (or average energy) per 𝑔 molecule of a monoatomic gas is given by
3 1 1 3
a) 𝑅𝑇 b) 𝑘𝑇 c) 𝑅𝑇 d) 𝑘𝑇
2 2 2 2
7. A cylinder of fixed capacity 44.8 𝑙𝑖𝑡𝑟𝑒 contains a monoatomic gas at standard temperature
and pressure. The amount of heat required to cylinder by 10℃ will be
(𝑅 = universal gas constant)
30𝑅
a) 𝑅 b)10𝑅 c) 20𝑅 d)
8. Air is pumped into an automobile tube upto a pressure of 200 kPa in the morning
when the air temperature is 22℃. During the day, temperature rises to 42℃ and the
tube expands by 2%. The pressure of the air in the tube at this temperature, will be
approximately
a) 212 kPa b) 209 kPa c) 206 kPa d) 200 kPa
9. The volume of a gas at pressure 21 × 104𝑁/𝑚2 and temperature 27℃ is 83 𝑙𝑖𝑡𝑟𝑒𝑠. If 𝑅 = 8.3
𝐽/𝑚𝑜𝑙 𝐾, then the quantity of gas in 𝑔 - 𝑚𝑜𝑙𝑒 will be
a) 15 b)42 c) 7 d)14
10. What is an ideal gas?
a) One that consists of molecules b) A gas satisfying the assumptions of
kinetic theory
c) A gas having Maxwellian distribution of d) A gas consisting of massless particles
speed
11. The relation between the gas pressure 𝑃 and average kinetic energy per unit volume 𝐸 is
1 3 2
a) 𝑃 = 𝐸 b)𝑃 = 𝐸 c) 𝑃 = 𝐸 d) 𝑃 = 𝐸
2 2 3
12. For a gas 𝛾 = 7/5. The gas may probably be
a) Helium b)Hydrogen c) Argon d)Neon
13. When a vander waal’s gas undergoes free expansion then its temperature
a) Decreases b)Increases
c) Does not change d)Depends upon the nature of the gas
14. If the oxygen (𝑂2) has root mean square velocity of 𝐶 𝑚𝑠-1, then root mean square velocity
of the hydrogen (𝐻2) will be
1 𝐶
a) 𝐶 𝑚𝑠-1 b) 𝑚𝑠-1 c) 4𝐶 𝑚𝑠-1 d) 𝑚𝑠-1
𝐶 4
15. A gas at the temperature 250 𝐾 is contained in a closed vessel. If the gas is heated through 1
𝐾, then the percentage increase in its pressure will be
a) 0.4% b)0.2% c) 0.1% d)0.8%
16. To what temperature should the hydrogen at room temperature (27℃) be heated at
constant pressure so that the R.M.S. velocity of its molecules becomes double of its previous
value
a) 1200℃ b)927℃ c) 600℃ d)108℃
17. Consider a collection of a large number of particles each with speed 𝑣. The direction of
velocity is randomly distributed in the collection. What is the magnitude of the relative
velocity between a pairs in the collection
a) 2𝑉/𝜋 b)𝑉/𝜋 c) 8𝑉/𝜋 d)4𝑉/𝜋
18. A pressure cooker contains air at 1 𝑎𝑡𝑚 and 30℃. If the safety value of the cooler blows
when the inside pressure ≥ 3 𝑎𝑡𝑚, then the maximum temperature of the air, inside the
cooker can be
a) 90℃ b)636℃ c) 909℃ d)363℃
19. The value of 𝑝𝑉 for one mole of an ideal gas is nearly equal to
𝑇
a) 2 J mol-1 K-1 b) 8.3 J mol-1 K-1 c) 4.2 J mol-1 K-1 d) 2 cal mol-1 K-1
20. 𝐶𝑂2(𝑂 - 𝐶 - 𝑂) is a triatomic gas. Mean kinetic energy of one gram gas will be (If 𝑁-
Avogadro’s number, 𝑘-Boltzmann’s constant and molecular weight of 𝐶𝑂2 = 44)
a) (3/88)𝑁𝑘𝑇 b)(5/88)𝑁𝑘𝑇 c) (6/88)𝑁𝑘𝑇 d)(7/88)𝑁𝑘𝑇
