engineering recuitment NMDC Junior Officer (Trainee) Mock Test 2024 Heat Transfer Radiation Laws of Radiation
A small disc-shaped earth satellite, 1 m in diameter, circles the earth at a distance of 300 km from the surface. The flat surface of the disc (with emissivity 0.3 and temperature -18°C is oriented tangentially to the earth’s surface with a view factor of 0.91. Average Earth temperature is ~27°C while the surrounding of the satellite is 0 K. Net rate at which energy is leaving the satellite is
1
0.003 W
2
14.5 W
3
-52.0 W
4
42.0 W