$1)$ A black body is at a temperature T $=3400$K

a$.$ Determine the wavelength amas, corresponding to the maximum black body

spectral emissive power at this temperature T b$.$ Write down the value of Eh$,$ at Amax.

c$.$ What is the fraction of the black body emissive power of this body in $(1)0-0\mathrm{.}4$ um $(1)0\mathrm{.}4-0\mathrm{.}7$m and $($ii$)0\mathrm{.}7-100$m$?$

d$.$ Determine the value of A for which $60\%$ of the total emissive power of the black body is contained in the interval $0-2.$