An apple of radius R is losing heat steadily and uniformly from its outer surface to the a...

An apple of radius R is losing heat steadily and uniformly from its outer surface to the ambient air at temperature T∞ with a convection coefficient of h, and to the surrounding surfaces at temperature Tsurr (all temperatures are absolute temperatures) . Also, heat is generated within the apple uniformly at a rate of egen per unit volume. If Ts denotes the outer surface temperature, the boundary condition at the outer surface of the apple can be expressed as

(a)

(b)

(c)

(d)

(e)   None of them