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Saturday, 31 October

JEE Main 2020 · PhysicsMultiple choiceMatch the listEasyRecall

JEE Main 4 September 2020, Shift 1, Physics Q8

Question 8 of 75 in this shift, Physics question 8 of 25.

Match the CP/CV\mathrm{C_P/C_V} ratio for ideal gases with different type of molecules : Molecule Type | CP/CV\mathrm{C_P/C_V} (A) Monatomic | (I) 7/5 (B) Diatomic rigid molecules | (II) 9/7 (C) Diatomic non-rigid molecules | (III) 4/3 (D) Triatomic rigid molecules | (IV) 5/3
  1. (1)(A)-(IV), (B)-(I), (C)-(II), (D)-(III)Official answer
  2. (2)(A)-(IV), (B)-(II), (C)-(I), (D)-(III)
  3. (3)(A)-(III), (B)-(IV), (C)-(II), (D)-(I)
  4. (4)(A)-(II), (B)-(III), (C)-(I), (D)-(IV)

Official answer

Option 1

NTA final key (Sep 2020).

Chapter
Kinetic Theory
Topic
Kinetic Theory of Gases
Idea tested
Gamma and Degrees of Freedom

Same idea in other shifts

Asked 9× in all
  1. 5 Apr 2026, Shift 1 · Q32Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Statement I: Change in internal…MediumTwo statements
  2. 7 Apr 2025, Shift 1 · Q33Match the LIST-I with LIST-I LIST-I | LIST-II A. Triatomic rigid gas | I. CpCv=53\frac{C_p}{C_v} = \frac{5}{3} B. Diatomic non-rigid gas | II.…MediumMatch the list
  3. 26 Jul 2022, Shift 2 · Q42A gas has nn degrees of freedom. The ratio of specific heat of gas at constant volume to the specific heat of gas at constant pressure…EasySingle correct
  4. 25 Jun 2022, Shift 2 · Q36The ratio of specific heats (CPCV)\left(\frac{C_P}{C_V}\right) in terms of degree of freedom (ff) is given by :EasySingle correct
  5. 26 Jun 2022, Shift 1 · Q39A thermally insulated vessel contains an ideal gas of molecular mass M and ratio of specific heats 1.4. Vessel is moving with speed vv…MediumSingle correct
  6. 17 Mar 2021, Shift 1 · Q8A polyatomic ideal gas has 24 vibrational modes. What is the value of γ\gamma ?MediumSingle correct
  7. 17 Mar 2021, Shift 2 · Q18If one mole of the polyatomic gas is having two vibrational modes and β\beta is the ratio of molar specific heats for polyatomic gas…MediumSingle correct
  8. 3 Sep 2020, Shift 2 · Q8To raise the temperature of a certain mass of gas by 50∘50^\circC at a constant pressure, 160 calories of heat is required. When the same…MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.