Transmission Of Heat Question 184
Question: Hot water kept in a beaker placed in a room cools from $ 70^{o}C $ to 60°C in 4 minutes. The time taken by it to cool from $ 69^{o}C $ to $ 59^{o}c $ will be
[JIPMER 1999]
Options:
A) The same 4 minutes
B) More than 4 minutes
C) Less than 4 minutes
D) We cannot say definitely
Show Answer
Answer:
Correct Answer: B
Solution:
Rate of cooling $ =\frac{-d\theta }{dt}\propto ( \frac{{\theta _{1}}+{\theta _{2}}}{2}-{\theta _{0}} ) $ In second case average temperature will be less hence rate of cooling will be less.
Therefore time taken will be more than 4 minutes.
BETA
