At the interface between one linear magnetic material and another, the magnetic field lines bend. the magnetic field b. in material 1 is at an angle θ1 to the normal direction at the interface, while in material 2 is at an angle θ2. (see the diagram in griffiths edition 4 figure 6.32). show that tan θ2/tan θ,-μ2jui, assuming there is no free current at the boundary

Consider a 1000 w iron whose base plate is made of 0.5 cm thick aluminum alloy 2024-t6 (ρ = 2770 kg/m3 and cp = 875 j/kg°c). the base plate has a surface area of 0.03 m2. initially, the iron is in thermal equilibrium with the ambient air at 22°c. assuming 90% of the heat generated in the resistance wires is transferred to the plate, determine the minimum time needed for the plate temperature to reach 200°c.