#### Question

A uniform slab of dimension 10 cm × 10 cm × 1 cm is kept between two heat reservoirs at temperatures 10°C and 90°C. The larger surface areas touch the reservoirs. The thermal conductivity of the material is 0.80 W m^{−1} °C^{−1}. Find the amount of heat flowing through the slab per minute.

#### Solution

Given:

Thermal conductivity of the material, *k* = 0.80 W m^{-1 } °c^{-1}Area of the cross section of the slab, A = 100 cm^{2 }= 10^{-2 }m^{2}Thickness of the slab, Δx = 1 cm = 10 ^{-2 }m

`"Rate of flow of heat" ="Temperature difference" / "Thermal resisstance"`

`⇒ (ΔQ)/(Δt) = (ΔT)/((Δx)/(kA)`

`(ΔQ)/(Δt) = ((90 - 10 ) k.A)/(Δx)`

`(ΔQ)/(Δt) = ((80) xx 0.8 xx 10^-2)/(Δx)1`

`(ΔQ)/(Δt)= 64 J //s`

`(ΔQ)/(Δt) = 64xx60 = 3840 J//min`

Is there an error in this question or solution?

Solution A Uniform Slab of Dimension 10 Cm × 10 Cm × 1 Cm is Kept Between Two Heat Reservoirs at Temperatures 10°C and 90°C. the Larger Concept: Thermal Expansion of Solids.