Two metallic spheres P and Q are of same surface finish and same density. Weight of P is twice that of Q. Both spheres are heated to same temperature and are left in room to cool by radiation. The ratio of initial rate of cooling of P to that of Q is
see full answer
Your Exam Success, Personally Taken Care Of
1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.
An Intiative by Sri Chaitanya
a
1:2
b
2:1
c
1:(2)1/3
d
(2)2/3:1
answer is C.
(Unlock A.I Detailed Solution for FREE)
Best Courses for You
JEE
NEET
Foundation JEE
Foundation NEET
CBSE
Detailed Solution
Let the mass of Q be m.∴mass of P = 2mNow, −m.s.dTdt=eσ.(4πR2)(T4−T04)⇒−dTdt=eσ.(4πR2)43πR3ρS(T4−T04)⇒−dTdt=3eσρS1R(T4−T04)∴−dTdt∝1RNow 43πRp3ρ=2×43πRQ3ρ⇒Rp=(2)1/3.RQ∴Initial rate of cooling of PInitial rate of cooling of Q=RQRP=1(2)1/3