A wire of length l and radius r is claimed rigidly at one end. When the other end of the wire is pulled by a force f, its length increases by l. What is the relationship between the force applied and the change in length of the wire?
1) The force applied is directly proportional to the change in length of the wire
2) The force applied is inversely proportional to the change in length of the wire
3) The force applied is equal to the change in length of the wire
4) The force applied has no effect on the change in length of the wire