🔥 Kinetic Theory of Gases – Stage 3 (Page 2)

Advanced Objective Problems (JEE Advanced)

This page focuses on distribution logic, collision theory, and microscopic interpretation. Most students lose marks here due to shallow understanding.

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🔹 Question 1 (Multi-Correct – Speed Distribution)

For a gas in thermal equilibrium, which statements are correct?

• A) Most probable speed is less than RMS speed
• B) Average speed equals RMS speed
• C) Speed distribution depends on temperature
• D) Fraction of fast molecules increases with temperature

Correct Answers: A, C, D

Key Insight:

• v_mp < v_avg < v_rms
• Temperature reshapes Maxwell curve

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🔹 Question 2 (Conceptual – Mean Free Path)

Mean free path of a gas molecule depends on:

• A) Temperature
• B) Pressure
• C) Molecular diameter
• D) Volume of container

Correct Answers: B, C

Explanation: Mean free path ∝ 1 / (pressure × molecular cross-section)

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🔹 Question 3 (Integer Type – Collision Frequency)

If pressure of an ideal gas is doubled at constant temperature, by what factor does collision frequency of a molecule increase?

Solution:

• Collision frequency ∝ number density
• Number density ∝ pressure

Answer: 2

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🔹 Question 4 (Trap – Temperature Interpretation)

Which statement about temperature is incorrect?

• A) Temperature is proportional to average kinetic energy
• B) At 0 K, molecular motion stops completely
• C) Temperature is a macroscopic quantity
• D) Different gases at same T have same average KE

Correct Answer: B

Why? Quantum effects prevent complete stoppage of motion.

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🔹 Question 5 (Assertion–Reason)

Assertion (A): Pressure of a gas is independent of the nature of the container walls.

Reason (R): Pressure depends on momentum transfer during molecular collisions.

Correct Option: Both A and R are true, and R explains A.

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🔹 Question 6 (Advanced Logic – Very Important)

Two gases have same RMS speed but different molar masses. Which must be same?

• A) Temperature
• B) Pressure
• C) Average kinetic energy per molecule
• D) Mean free path

Correct Answers: A, C

Logic: v_rms = √(3kT/m) → Same speed implies same T only if KE matches.

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🧠 Examiner’s Golden Rule (Remember)

• Speed → mass dependent
• Energy → temperature dependent
• Pressure → collision dependent

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✅ Stage 3 – Page 2 Completed

📚 IIT–JEE Physics Complete Library (Class XI)

Curated for IIT-JEE Advanced Aspirants
Concepts • Numericals • Objective Questions • Revision Capsules

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🔥 Kinetic Theory of Gases (KTG) – Complete Library

1. KTG – Part 1
2. KTG – Part 2
3. KTG – Part 3
4. KTG – Part 4
5. KTG – Part 5
6. KTG – Part 6
7. KTG – Part 7
8. KTG – Special Notes
9. KTG – Part 9
10. KTG – Part 10
11. KTG – Part 11
12. KTG – Part 12
13. KTG – Part 13
14. KTG – Part 14
15. KTG – Part 15
16. KTG – Part 16
17. KTG – Part 17
18. KTG – Part 18
19. KTG – Part 19
20. KTG – Part 20
21. KTG – Part 21
22. KTG – Part 22
23. KTG – Part 23
24. KTG – Part 24
25. KTG – Part 25
26. KTG – Part 26
27. KTG – Part 27
28. KTG – Part 28
29. KTG – Part 29
30. KTG – Part 30

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📐 Properties of Matter – Complete IIT-JEE Library

1. Properties – Part 1
2. Properties – Part 2
3. Properties – Part 3
4. Properties – Part 4
5. Properties – Part 5
6. Properties – Part 6
7. Properties – Part 7
8. Properties – Part 8
9. Properties – Part 9
10. Properties – Part 10
11. Properties – Part 11
12. Properties – Part 12
13. Properties – Part 13
14. Properties – Part 14
15. Properties – Part 15
16. Properties – Part 16
17. Properties – Part 17
18. Properties – Part 18
19. Properties – Part 19
20. Properties – Part 20
21. Properties – Part 21
22. Properties – Part 22
23. Properties – Part 23
24. Properties – Part 24
25. Properties – Part 25

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🌟 Master & Mega Physics Libraries

• IIT-JEE Physics Master Library
• Physics Complete Mega Library
• SHM Complete Library
• Waves – JEE Advanced Library
• Gravitation Library
• Momentum & Collisions Library
• Centre of Mass Library
• Work Energy Power Library

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