JEE Main 2021 · PhysicsMultiple choiceSingle correctMediumRecall

JEE Main 24 February 2021, Shift 1, Physics Q7

Question 7 of 90 in this shift, Physics question 7 of 30, Section A.

If Y, K and

\eta

are the values of Young’s modulus, bulk modulus and modulus of rigidity of any material respectively. Choose the correct relation for these parameters.

(1) $Y=\frac{9K\eta}{2\eta+3K}\ \mathrm{N/m^{2}}$
(2) $Y=\frac{9K\eta}{3K-\eta}\ \mathrm{N/m^{2}}$
(3) $K=\frac{Y\eta}{9\eta-3Y}\ \mathrm{N/m^{2}}$ Official answer
(4) $\eta=\frac{3YK}{9K+Y}\ \mathrm{N/m^{2}}$

Official answer

Option 3

NTA final key.

Chapter: Mechanical Properties of Solids
Topic: Elasticity
Idea tested: Interrelations Between Elastic Constants

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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.