JEE Main 2020 · MathsMultiple choiceSingle correctEasyCalculation

JEE Main 3 September 2020, Shift 2, Maths Q59

Question 59 of 75 in this shift, Maths question 9 of 25.

If the surface area of a cube is increasing at a rate of 3.6 cm

^2

/sec, retaining its shape; then the rate of change of its volume (in cm

^3

/sec.), when the length of a side of the cube is 10 cm, is :

(1)10
(2)9Official answer
(3)18
(4)20

Official answer

Option 2

NTA final key (Sep 2020).

Chapter: Application of Derivatives
Topic: Chain Rule
Idea tested: Chain Rule in Related Rates

Same idea in other shifts

Asked 5× 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 108 of the 174 JEE Main shifts held from 2017 to 2026.