JEE Main 2024 · MathsMultiple choiceSingle correctEasyApplication

JEE Main 31 January 2024, Shift 2, Maths Q13

Question 13 of 90 in this shift, Maths question 13 of 30, Section A.

The temperature

T(t)

of a body at time

t=0

160^\circ

F and it decreases continuously as per the differential equation

\frac{dT}{dt}=-K(T-80)

, where

K

is a positive constant. If

T(15)=120^\circ

F, then

T(45)

is equal to

(1) $80^\circ$ F
(2) $85^\circ$ F
(3) $90^\circ$ FOfficial answer
(4) $95^\circ$ F

Official answer

Option 3

NTA final key.

Chapter: Differential Equations
Topic: Variable Separable Form
Idea tested: Physical Modeling Applications

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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.