JEE Advanced 2014 Paper 2

A planet of radius R =

1

10

× (radius of Earth) has the same mass density as Earth. Scientists dig a well of depth

R

5

on it and lower a wire of the same length and of linear mass density 10−3kgm−1 into it. If the wire is not touching anywhere, the force applied at the top of the wire by a person holding it in place is (take the radius of Earth = 6×106m and the acceleration due to gravity of Earth is 10 ms−2