0 votes 0 votes For the enclosure formed between two concentric spheres as shown ($R_2 = 2R_1$), the fraction of radiation leaving the surface area $A_2$ that strikes itself is $1/4$ $1/2$ $1/\sqrt2$ $3/4$ Others gate2012 + – Milicevic3306 asked Mar 25, 2018 edited Mar 15, 2021 by soujanyareddy13 Milicevic3306 7.9k points answer See all 0 reply