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

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?