A 0.720 m long solenoid is formed by wrapping 430 turns of wire around a hollow cylinder with a radius of 0.230 m. At the instant when the magnetic field in the interior is 0.750 T, calculate the energy stored in the field.

Consider the growth of a 20-nm-diameter silicon nanowire onto a silicon wafer. the temperature of the wafer surface is maintained at 2400 k. assume the thermal conductivity of the silicon nanowire is 20 wm-1k-1 and all its surfaces including the tip are subjected to convection heat transfer with the coefficient h = 1×105 wm-2k-1 and t∞ = 8000 k. when the nanowire grows to l = 300 nm, what is the temperature of the nanowire tip (t (x =