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Two wires are made up of same material. Ratio of their masses is 1 : 2 and ratio of their lengths is 2 : 1 . So ratio of their resistances is.... . |
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Answer» `1: 4` `R= (RHO l)/(A) rArr R = (rho l^(2))/(V)"" [ because Al = V] ` `R = (rho l^(2))/((m)/(d)) ( because " VOLUME" = ("mass")/("density"))` Material is same, so `rho` and d are constant. `therefore R PROP (l^(2))/(m)` `therefore (R_(1))/(R_(2)) = ((l_(1))/(l_(2)))^(2) xx ((m_(2))/(m_(1))) ` = ` (2)^(2)xx (2)` `= 4 xx 2 = 8` `therefore R_(1) : R_(2) = 8 : 1 ` |
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