JEE Main 2020PhysicsThermal Properties of MatterHardMCQ

JEE Main 2020 — Thermal Properties of Matter Question with Solution

JEE Main 2020 (03 Sep Shift 2)

Question

A metallic sphere cools from 50 °C to 40 °C in 300 s. If atmospheric temperature around is 20 °C, then the sphere's temperature after the nest 5 minutes will be close to:

Choose an option

Show full solutionCorrect option: B
Correct answer
B33 °C

Step-by-step explanation

Using Newton's Law of cooling

50-405 min=K50+402-20     ......(i)

Next 5 min.

40-θ5=K40+θ2-20     .....(ii)

Dividing (ii)/(i)

40-θ10=40+θ-4050+40-40=θ50

40-θ=θ5

200-5θ=θ

∴   θ=2006=33.3 °C

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About this question

This is a previous-year question from JEE Main 2020, covering the Thermal Properties of Matter chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.