1. Show that the hemispherical black cavity with a flat cover over it emits 50% of radiation to the surface itself and is absorbed. 2. Explain the electrical analogy for radiative heat transfer in a...

1. Show that the hemispherical black cavity with a flat cover over it emits 50% of radiation to the surface itself and is absorbed.

2. Explain the electrical analogy for radiative heat transfer in a black enclosure. Draw the equivalent electrical network for radiative flux between four walls of a black enclosure.