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An array of 10 fins of anodized aluminum (k = 180W/m K) is used to cool a transistor operating at a location where the ambient conditions correspond to temperature 35 degree Celsius and convective coefficient 12W/square m K. The distance AB is 3 mm, EF is 0.4 mm. The length of the fin is 5 mm and has its base at 60 degree Celsius. Find the power dissipated by the fin array?

An array of 10 fins of anodized aluminum (k = 180W/m K) is used to cool a transistor operating at a location where the ambient conditions correspond to temperature 35 degree Celsius and convective coefficient 12W/square m K. The distance AB is 3 mm, EF is 0.4 mm. The length of the fin is 5 mm and has its base at 60 degree Celsius. Find the power dissipated by the fin array? Correct Answer 0.786W

P = 2(3 + 0.4) = 6.8 mm, A = (3) (0.4) = 1.2 square meter, m = 19.44 per meter. So, Q = k A m (t 0 –ta) tan h ml = 0.0786, therefore heat loss from the array of 10 fins = (0.0786) (10) = 0.786W.

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