JEE Main 2020 · PhysicsMultiple choiceSingle correctHardMulti-step

JEE Main 8 January 2020, Shift 1, Physics Q6

Question 6 of 75 in this shift, Physics question 6 of 25, Section A.

Consider a solid sphere of radius R and mass density

\rho(r) = \rho_0\left(1-\frac{r^2}{R^2}\right)

0 < r \le R

. The minimum density of a liquid in which it will float is :

(1) $\frac{\rho_0}{5}$
(2) $\frac{\rho_0}{3}$
(3) $\frac{2\rho_0}{5}$ Official answer
(4) $\frac{2\rho_0}{3}$

Official answer

Option 3

NTA final key (Jan 2020).

Chapter: Mechanical Properties of Fluids
Topic: Fluid Statics
Idea tested: Law of Floatation

Same idea in other shifts

Asked 3× in all

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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 42 of the 174 JEE Main shifts held from 2017 to 2026.