A spherical metal ball of radius r_0 is heated in an oven to a temperature of T_1 throughout and is then taken out of the oven a
nd allowed to cool in ambient air at T[infinity] , by convection and radiation. The emissivity of the outer surface of the cylinder is e, and the temperature of the surrounding surfaces is T_{surr}. The average convection heat transfer coefficient is estimated to be h. Assuming variable thermal conductivity and transient one-dimensional heat transfer, express the mathematical formulation (the differential equation and the boundary and initial conditions) of this heat conduction problem.
Oleg is a mustimeter or multi tester or a basic voltage tester which is used to test the ground. The main purpose of the tester is to ensure that the outlet is connected to the ground of the circuit, thereby ensuring its proper functioning.
