$4)$ The element of an electric stove heats up from $293$ K $(20$ celsius$)$ to $1000$ K when

turned on full power.

a$)$ Calculate the difference in blackbody power output per m$2$ between the stove

element at these two temperatures.

b$)$ One will observe the element glowing red $($wavelength around $700$ nm$)$ when

at max power, but not while it is off. Mathematically explain this observation using

Planck$$s Blackbody Radiation Law