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A lump body cools from 90°C to 80°C in 5 minutes. Under the same external conditions, to cool from 80°C to 70°C the body will take
- a)5 minutes
- b)4 minutes
- c)2.5 minutes
- d)More than 5 minutes
Correct answer is option 'D'. Can you explain this answer?
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Verified Answer
A lump body cools from 90°C to 80°C in 5 minutes. Under the same exte...
For a lump, the temperature decreases exponentially with time and the rate of fall of temperature in the beginning will be faster and then it slows down.
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Therefore, if time taken by the body in cooling from 90°C to 80°C is 5 min, then definitely time taken by the body in cooling from 80°C to 70°C will be more than 5 minutes.
Most Upvoted Answer
A lump body cools from 90°C to 80°C in 5 minutes. Under the same exte...
Understanding Cooling Rates
When a lump body cools, the rate of heat loss is generally described by Newton's Law of Cooling, which states that the rate of cooling is proportional to the temperature difference between the object and its surroundings.
Cooling Process Analysis
- Initial Cooling: The body cools from 90°C to 80°C.
- Time Taken: This process takes 5 minutes.
- Temperature Difference: The temperature difference during this cooling is 10°C (90°C - 80°C).
Subsequent Cooling Scenario
- Next Cooling Phase: The body now cools from 80°C to 70°C.
- New Temperature Difference: The temperature difference in this phase is again 10°C (80°C - 70°C), but the surrounding temperature has remained constant.
Key Insight
- Cooling Rate Dependency: The cooling rate decreases as the temperature of the body approaches the ambient temperature. The body will lose heat more slowly due to a smaller effective temperature difference compared to the previous phase.
Conclusion
- Time Estimation: Because the body cools from a higher temperature (90°C) to a lower temperature (80°C) faster than from 80°C to 70°C, the time taken to cool from 80°C to 70°C will be more than 5 minutes.
Thus, the correct answer is option D, indicating that it will take longer than the initial 5 minutes for the body to cool from 80°C to 70°C due to the diminishing temperature gradient.
When a lump body cools, the rate of heat loss is generally described by Newton's Law of Cooling, which states that the rate of cooling is proportional to the temperature difference between the object and its surroundings.
Cooling Process Analysis
- Initial Cooling: The body cools from 90°C to 80°C.
- Time Taken: This process takes 5 minutes.
- Temperature Difference: The temperature difference during this cooling is 10°C (90°C - 80°C).
Subsequent Cooling Scenario
- Next Cooling Phase: The body now cools from 80°C to 70°C.
- New Temperature Difference: The temperature difference in this phase is again 10°C (80°C - 70°C), but the surrounding temperature has remained constant.
Key Insight
- Cooling Rate Dependency: The cooling rate decreases as the temperature of the body approaches the ambient temperature. The body will lose heat more slowly due to a smaller effective temperature difference compared to the previous phase.
Conclusion
- Time Estimation: Because the body cools from a higher temperature (90°C) to a lower temperature (80°C) faster than from 80°C to 70°C, the time taken to cool from 80°C to 70°C will be more than 5 minutes.
Thus, the correct answer is option D, indicating that it will take longer than the initial 5 minutes for the body to cool from 80°C to 70°C due to the diminishing temperature gradient.
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A lump body cools from 90°C to 80°C in 5 minutes. Under the same external conditions, to cool from 80°C to 70°C the body will takea) 5 minutesb) 4 minutesc) 2.5 minutesd) More than 5 minutesCorrect answer is option 'D'. Can you explain this answer?
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A lump body cools from 90°C to 80°C in 5 minutes. Under the same external conditions, to cool from 80°C to 70°C the body will takea) 5 minutesb) 4 minutesc) 2.5 minutesd) More than 5 minutesCorrect answer is option 'D'. Can you explain this answer? for Chemical Engineering 2024 is part of Chemical Engineering preparation. The Question and answers have been prepared according to the Chemical Engineering exam syllabus. Information about A lump body cools from 90°C to 80°C in 5 minutes. Under the same external conditions, to cool from 80°C to 70°C the body will takea) 5 minutesb) 4 minutesc) 2.5 minutesd) More than 5 minutesCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for Chemical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A lump body cools from 90°C to 80°C in 5 minutes. Under the same external conditions, to cool from 80°C to 70°C the body will takea) 5 minutesb) 4 minutesc) 2.5 minutesd) More than 5 minutesCorrect answer is option 'D'. Can you explain this answer?.
A lump body cools from 90°C to 80°C in 5 minutes. Under the same external conditions, to cool from 80°C to 70°C the body will takea) 5 minutesb) 4 minutesc) 2.5 minutesd) More than 5 minutesCorrect answer is option 'D'. Can you explain this answer? for Chemical Engineering 2024 is part of Chemical Engineering preparation. The Question and answers have been prepared according to the Chemical Engineering exam syllabus. Information about A lump body cools from 90°C to 80°C in 5 minutes. Under the same external conditions, to cool from 80°C to 70°C the body will takea) 5 minutesb) 4 minutesc) 2.5 minutesd) More than 5 minutesCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for Chemical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A lump body cools from 90°C to 80°C in 5 minutes. Under the same external conditions, to cool from 80°C to 70°C the body will takea) 5 minutesb) 4 minutesc) 2.5 minutesd) More than 5 minutesCorrect answer is option 'D'. Can you explain this answer?.
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A lump body cools from 90°C to 80°C in 5 minutes. Under the same external conditions, to cool from 80°C to 70°C the body will takea) 5 minutesb) 4 minutesc) 2.5 minutesd) More than 5 minutesCorrect answer is option 'D'. Can you explain this answer?, a detailed solution for A lump body cools from 90°C to 80°C in 5 minutes. Under the same external conditions, to cool from 80°C to 70°C the body will takea) 5 minutesb) 4 minutesc) 2.5 minutesd) More than 5 minutesCorrect answer is option 'D'. Can you explain this answer? has been provided alongside types of A lump body cools from 90°C to 80°C in 5 minutes. Under the same external conditions, to cool from 80°C to 70°C the body will takea) 5 minutesb) 4 minutesc) 2.5 minutesd) More than 5 minutesCorrect answer is option 'D'. Can you explain this answer? theory, EduRev gives you an
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