Answer :
The heat flow of the thermal resistance is (r2 - r1) / 4πkr1r2).
Consider the diagram below, the heat flow will be
Fourier's law in radial coordinates
qr = -k.AdT/dr
Substituting the values of the area of sphere,
qr = -k (4πr²) dT/dr
Integrating we get
qr/4π∫dr/r^2 = ∫kdt
qr/4π ∫dr/r^2 = ∫kdt
qr/4π (1/r1 - 1/r2) = k(t2-t1)
qr = 4πkr1r2(t1-t2) / (r2 - r1)
The thermal resistance is expressed as
R = (r2 - r1) / 4πkr1r2)
Therefore, the heat flow of the thermal resistance is (r2 - r1) / 4πkr1r2).
To know more about heat flow, refer: https://brainly.com/question/13791231
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