1. 3/2T 2. 4/3T 3. T 4. 7/4T

Answer: 1. 3/2T Use Newton's law in the average form: rate of fall =k (mean temperature-T) . First 10 min: 3T-2T/10=k(3T+2T/2-T)=k·3/2T , so k=2/3 per 10 min. Next 10 min, final temperature x : 2T-x=2/3(2T+x/2-T)=2/3·x/2=x/3 . So 2T=4/3x , giving x=3/2T . Option (1).

Topic: Heat transfer: conduction, convection, radiation· Properties of Solids and Liquids

A body cools from a temperature 3T to 2T in 10 minutes. The room temperature is T. Assume that Newton's law of cooling is applicable. The temperature of the body at the end of next 10 minutes will be

1. \(\frac{3}{2}T\)

2. \(\frac{4}{3}T\)

3. \(T\)

4. \(\frac{7}{4}T\)

Doubtly Asked 30 Oct 2026 NEET UG 2016 Phase 2 neet Save WhatsApp Report

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Answer: 1. \(\frac{3}{2}T\)

Use Newton's law in the average form: rate of fall \(=k\,(\text{mean temperature}-T)\).

First 10 min: \(\dfrac{3T-2T}{10}=k\left(\dfrac{3T+2T}{2}-T\right)=k\cdot\tfrac32T\), so \(k=\dfrac{2}{3}\) per 10 min.
Next 10 min, final temperature \(x\): \(2T-x=\dfrac23\left(\dfrac{2T+x}{2}-T\right)=\dfrac23\cdot\dfrac x2=\dfrac x3\).

So \(2T=\tfrac43x\), giving \(x=\tfrac32T\). Option (1).

Doubtly AI · 30 Oct 2026 AI-generated · not yet verified Report

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A body cools from a temperature 3T to 2T in 10 minutes. The room temperature is T. Assume that Newton's law of cooling is applicable. The temperature of the body at the end of next 10 minutes will be

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