A semiconductor wafer with n-type impurities has been stripped from all its free electrons. The wafer is in the form of a flat disk and has positive charges uniformly distributed on its top and bottom surface. The charge density is 10 C/cm^2. Determine the magnitude of the electric flux density D above the wafer in C/m^2.a. 0.5 x10+5 c/m2 b. 0.5x10-5 C/m2 c. 0.5x10 C/m2 d. 10+5 C/m2

A2-m rigid tank initially contains saturated water vapor at 100 kpa. the tank is connected to a supply line through a valve. steam is flowing in the supply line at 600 kpa and 300 c. the valve is opened, and steam is allowed to enter the tank until the pressure in the tank reaches the line pressure, at which point the valve is closed. a thermometer placed in the tank indicates that the temperature at the final state is 200°c. determine (a) the mass of steam that has entered the tank (b) the amount of heat transfer.