please see below question?

Question

two bones of equal radius are subjected to equal twisting torques. if one is longer than the other, which will fracture first? explain.

Answer 1

OK.
the shorter will fracture first.
when you apply a twisting torque to slide (2XRadius = length) it will be fractured into two parts...... and if you do this to a (length=infinity) nothing will happen.
you can look at things this way.... there is another way like imagining or applying physics laws.......
this way sometimes is wrong because you should look at the matter u are dealing with

Answer 2

The longer one......

Think of when you break a stick over your knee - its easier to break a long stick - the shorter one needs more force.