wiz-icon
MyQuestionIcon
MyQuestionIcon
9
You visited us 9 times! Enjoying our articles? Unlock Full Access!
Question

A solid copper sphere of density ρ, specific heat c and radius r is at temperature T1. It is suspended inside a chamber whose walls are at temperature 0 K. The time required for the temperature of sphere to drop to T2 is rρcxeσ(1T321T31). Find the value of x ?
Take the emmissivity of the sphere to be equal to e.

Open in App
Solution

Rate of heat loss dQdt=eAσT4
mc(dTdt)=eAσT4
Temperature decreases with time
m=43πr3ρ,A=4πr2

dTdt=3eσρcrT4t0 dt=rρc3eσT2T1dTT4t=+rρc9eσ[1T321T31] x=9

flag
Suggest Corrections
thumbs-up
2
Join BYJU'S Learning Program
Join BYJU'S Learning Program
CrossIcon