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1.56xx10^(5) heat energy is transferred ...

`1.56xx10^(5)` heat energy is transferred through wall 2 `m^(2)` and 12 cm thickness in every hour. Temperature difference between two walls is `20^(@)C`, the mall conductivity of material of wall is . . . .. .`"Wm"^(-1)K^(-1)`

A

`0.11`

B

`0.13`

C

`0.15`

D

`1.2`

Text Solution

Verified by Experts

The correct Answer is:
B
Here, `A="2 m"^(2)`
`L=12cm=0.12m`
`H=1.56xx10^(5)J`
`t=1" hour "=3600s`
`T_(1)-T_(2)=20^(@)C` or 20 K
Heat conducted in time .t. in thermal steady state,
`H=(kA(T_(1)-T_(2)))/(L)xxt`
`:.k=(HL)/(A(T_(1)-T_(2))xxt)`
`=(1.56xx10^(5)xx0.12)/(2xx20xx3600)`
`=0.0000013xx10^(5)`
`:.k=0.13" W m"^(-1)K^(-1)`
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