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Three rods AB, BC and BD of same length...

Three rods `AB, BC` and `BD` of same length l and cross-sectionsl area `A` are arranged as shown . The end `D` is immersed in ice whose mass is `440 gm` Heat is being supplied at constant rate of `200cal//sec` from the end Time in which whole ice will melt (Latent heat of fusion of ice is `80cal//gm`
.

A

`(40)/(3)min`

B

`700sec`

C

`20//3min`

D

indefinitely long time

Text Solution

Verified by Experts

If `theta` be temperature of `B`, then
`(2kA(theta-100))/(l)+((k//2)A(theta-0))/(l)=200`
Substituting value `theta=880^(@)C`
`:. Phi_(1)=mL`
`(kA(880-0))/(2l)xxt=440xx80`
`t=(80xx1xx2xx440)/(100xx10xx10^(-4)xx880)=800sec=(40//3)min`
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