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Two wires of same material have their lengths in the ratio 2:3 and radii 8:9 . Equal value of p.d is applied between their ends (separately). Calculate the ratio of current through those two |
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Answer» Solution :We know that `R= (rhol)/(A) =(rhol)/(pir^2)` `R= (rhol)/(pir^2)` SUBSTITUTE `R= V/I` `V/I =(rhol)/(pir^2) impliesI = (Vpir^2)/(rhol)` `I PROP (r^2)/(l)` `(I_1)/(I_2) =(r_1^2)/(l_1) XX(l_2)/(r_2^2)` `(I_1)/(I_2) =(r_1^2)/(r_2^2) xx ((l_2)/(l_1)) = (8^2 xx 3)/(9^2 xx 2) =(64xx3)/(81xx2) = (32)/(27)` `I_1 :I_2 =32:27` |
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