The correct answer is: B. Decreases below the neutral axis and increases above the neutral axis.
Diagonal tension is a type of shear stress that occurs in beams when they are subjected to bending. It is caused by the difference in the vertical displacement of the top and bottom fibers of the beam. The top fibers are in tension, while the bottom fibers are in compression. The diagonal tension is maximum at the neutral axis, and decreases below the neutral axis and increases above the neutral axis.
The following diagram shows the distribution of diagonal tension in a beam:
[Diagram of a beam with diagonal tension]
The diagonal tension is represented by the arrows. The arrows are pointing in the direction of the shear stress. The arrows are longest at the neutral axis, and get shorter as you move away from the neutral axis.
The following is a brief explanation of each option:
- Option A: Diagonal tension is maximum at the neutral axis. This is incorrect because the diagonal tension is actually maximum at the top and bottom fibers of the beam, and is zero at the neutral axis.
- Option B: Diagonal tension decreases below the neutral axis and increases above the neutral axis. This is the correct answer.
- Option C: Diagonal tension increases below the neutral axis and decreases above the neutral axis. This is incorrect because the diagonal tension actually decreases below the neutral axis and increases above the neutral axis.
- Option D: Diagonal tension remains same. This is incorrect because the diagonal tension actually decreases below the neutral axis and increases above the neutral axis.