1.

The length of a metal wire is l_(1) when the tension is F_(1) and is 12 when the tension is F_(2). The original length of wire is:

Answer»

`(l_(1)+l_(2))/2`
`SQRT(F_(1)F_(2)l_(1)l_(2))`
`(l_(1)F_(2)+l_(2)F_(1))/(F_(1)+F_(2))`
`(l_(1)F_(2)-l_(2)F_(1))/(F_(2)-F_(1))`

Solution :If L is the ORIGINAL length, then
CHANGE in length with `F_(1) = l_(1) -L`
Change in length with `F_(2) = l_(2) - L`
Here `Y=(F_(1))/AxxL/(l_(1)-L)=(F_(2))/AxxL/(l_(2)-L)`
`F_(1)l_(2)-F_(1)L=F_(2)l_(1)-F_(2)L`
`L(F_(2)-F_(1))=F_(2)l_(1)-F_(1)l_(2)`
`L=(F_(2)l_(1)-F_(1)l_(2))/(F_(2)-F_(1))`
Correct choice is (d).


Discussion

No Comment Found

Related InterviewSolutions