If a = 0.72 and r = 0.24, then the value of tr is ______.

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If a = 0.72 and r = 0.24, then the value of tr is 0.04. Explanation: Express the relation of absorptivity. The fraction of light/ray/radiation absorbed by a surface is called absorptivity. a = (G_(abs))/G G_(abs) =Ga Here, G_(abs) is absorbed radiation and G is incident radiation. Express the relation of reflectivity. The fraction of light reflected by a surface is known as reflectivity. r = (G_(ref))/G G_(ref) = Gr Here, G_(ref) is reflected radiation. Express the relation of transmissivity. The fraction of light/ray/radiation transmitted by a surface is known as transmissivity. t_r = G_t/G G_t = Gt_r Here, G_t is transmitted radiation. Express the relation of 1st law of thermodynamics. Sum of all radiation (absorbed, reflected and transmitted) should be equals to the total radiation. G_(abs) + G_(ref) + G_t = G ......(i) Substitute Ga for G_(abs), G_r for G_(mf) and Gt for Gt in equation (i). (Ga)/G + (Gr)/G + (Gt_r)/G = 1 a + r + t_r = 1 Substitute 0.72 for a and 0.24 for r to find transmitted radiation. 0.72 + 0.24 + tr = 1 tr = 1 – 0.96 tr = 0.04

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