AB is an iron wire, CD is a copper wire of same length and same cross-section as AB. The rod BD is 80cm long. A load of 2kgwt is suspended from the rod. At what distance x, should the load be suspended from the point B for the rod to remains in horizotal position.

AB is an iron wire, CD is a copper wire of same length and same cross-

1.	AB is an iron wire, CD is a copper wire of same length and same cross-section as AB. The rod BD is 80cm long. A load of 2kgwt is suspended from the rod. At what distance x, should the load be suspended from the point B for the rod to remains in horizotal position.
Answer» Solution :`Y_(CU)=11.8xx10^(10)(N)/(m^(2)), Y_(Fe)=19.6xx0^(10)(N)/(m^(2))` The rod will remain horizontal if elongation of both the wires is same `e_(1)=e_(2)` `(T_(1)L)/(pir^(2)Y_(1))=(T_(2)gL)/(pir^(2)Y_(2)) RARR(T_(1))/(Y_(1))=(T_(2))/(Y_(2))=(T_(1))/(T_(2))=(Y_(1))/(Y_(1))=(11.8xx10^(10))/(19.6xx10^(10))=(59)/(98)` `T_(2)=T_(1)(80-x),(98)/(59)x=80- x rArr 98x=59xx80-59x` `157x=59xx80, x=(59xx80)/(157) rArr x= 30 cm`