Q39.Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R. JEE Main 2021 (20 Jul Shift 1) JEE Main Previous Year Paper Assertion A : Sharp glass edge becomes smooth on heating it up to its melting point. Reason R : The viscosity of glass decreases on melting. Choose the most appropriate answer from the options given below. (1) A is true but R is false (2) Both A and R are true but R is NOT the correct explanation of A. (3) A is false but R is true. (4) Both A and R are true and R is the correct explanation of A .
What This Question Tests
This assertion-reasoning question tests the understanding of the properties of amorphous solids like glass, specifically how heating affects its viscosity and the resulting change in shape due to surface tension.
Concepts Tested
📚 NCERT Sections This Tests
4.11 — Explain Giving Reasons:
Chemistry Class 11 · Chapter 4
4.11 Explain giving reasons: (i) Transition metals and many of their compounds show paramagnetic behaviour. (ii) The enthalpies of atomisation of the transition metals are high. (iii) The transition metals generally form coloured compounds. (iv) Transition metals and their many compounds act as good catalyst.
14.2 — Which Of The Statements Given In Exercise 14.1 Is True For P-Type
Physics Class 12 · Chapter 14
14.2 Which of the statements given in Exercise 14.1 is true for p-type semiconductos.
14.1 — In An N-Type Silicon, Which Of The Following Statement Is True:
Physics Class 12 · Chapter 14
14.1 In an n-type silicon, which of the following statement is true: (a) Electrons are majority carriers and trivalent atoms are the dopants. (b) Electrons are minority carriers and pentavalent atoms are the dopants. (c) Holes are minority carriers and pentavalent atoms are the dopants. (d) Holes are majority carriers and trivalent atoms are the dopants.
📋 Question Details
- Chapter
- Solid State
- Topic
- Properties of glass, viscosity
- Year
- 2021
- Shift
- 20 Jul Shift 1
- Q Number
- Q39
- Type
- Assertion Reasoning
- NCERT Ref
- Class 12 Chemistry Ch 1: Solid State
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