Correct option is D
In a cantilever beam, the highest bending moment occurs at the
fixed support end. Therefore, an increase in load at the free end is most likely to cause failure at the fixed support, where the bending stress is maximum.
At the free end: Incorrect, as this point experiences zero bending moment.
Anywhere in the beam: Incorrect, as failure is most likely at the location with the highest stress (the fixed support).
At the mid of its length: Incorrect, as the bending moment and stress increase towards the fixed end.
At the fixed support end: Correct, as this is where the maximum bending moment and stress occur.
Therefore, the correct answer is (d) At the fixed support end.
