A cup of coffee cools from \(90^{\circ}\text{C}\) to \(80^{\circ}\text{C}\) in \(t\) minutes, when the room temperature is \(20^{\circ}\text{C}.\) The time taken by a similar cup of coffee to cool from \(80^{\circ}\text{C}\) to \(60^{\circ}\text{C}\) at room temperature same at \(20^{\circ}\text{C}\) is:

1. \(\dfrac{10}{13}t\) 2. \(\dfrac{5}{13}t\)
3. \(\dfrac{13}{10}t\) 4. \(\dfrac{13}{5}t\)
Subtopic:  Newton's Law of Cooling |
 66%
Level 2: 60%+
NEET - 2021
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An object kept in a large room having an air temperature of \(25^\circ \text{C}\) takes \(12 ~\text{min}\) to cool from \(80^\circ \text{C}\) to \(70^\circ \text{C}.\) The time taken to cool for the same object from \(70^\circ \text{C}\) to \(60^\circ \text{C}\) would be nearly:

1. \(10 ~\text{min}\) 2. \(12 ~\text{min}\)
3. \(20 ~\text{min}\) 4. \(15 ~\text{min}\)
Subtopic:  Newton's Law of Cooling |
 79%
Level 2: 60%+
NEET - 2019
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