Transmission Of Heat Question 167
Question: Consider two hot bodies $ B _{1} $ and $ B _{2} $ which have temperatures $ 100^{o}C $ and $ 80^{o}C $ respectively at $ t=0 $ . The temperature of the surroundings is $ 40^{o}C $ . The ratio of the respective rates of cooling $ R _{1} $ and $ R _{2} $ of these two bodies at $ t=0 $ will be
[MP PET 1990]
Options:
A) $ R _{1}:R _{2}=3:2 $
B) $ R _{1}:R _{2}=5:4 $
C) $ R _{1}:R _{2}=2:3 $
D) $ R _{1}:R _{2}=4:5 $
Show Answer
Answer:
Correct Answer: A
Solution:
Initially at t = 0 Rate of cooling (R) µ Fall in temperature of body (q ? q0)
Therefore $ \frac{R _{1}}{R _{2}}=\frac{{\theta _{1}}-{\theta _{0}}}{{\theta _{2}}-{\theta _{0}}}=\frac{100-40}{80-40}=\frac{3}{2} $
BETA
