InterviewSolution
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InterviewSolution
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Two exactly similar wires of steel and copper are stretched by equal forces. If the total elogation is 1cm. Find by how much is each wire elongated ? Given Y for steel ` = 20 xx 10^(11) dyn e//cm^2 and Y for copper = 12xx10^(11) dyn e//cm^2` |
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Answer» Correct Answer - 0.375 cm and 0.625 cm `Delta l_s + Delta l_c = 1 cm………. (i)` `Y_s = (F)/(A)xx(l)/(Delta l_s) and Y_c = (F)/(A)xx(l)/(Delta l_c)` `:. (Y_s)/(Y_c) = (Delta l_c)/(Delta l_s)` `or Delta l_c = Delta l_s xx(Y_s)/(Y_c) = Delta l_s xx (20 xx 10^(11))/(12 xx 10(11)) = (5)/(3) Delta l_s` From (i), `Delta l_s = (3)/(8) cm = 0.375 cm` `Delta l_c = (5)/(3) xx (3)/(8) = (5)/(8) cm = 0.625 cm` |
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