A built-in, fixed support has how many reactions and moment?

A built-in, fixed support has how many reactions and moment?

• A. 1 reaction and 1 moment
• B. 2 reactions and 1 moment
• C. 1 reaction and 2 moments
• D. 2 reactions and no moment

Answer: (B)

A built-in, fixed support prevents movement in both horizontal and vertical directions and also stops rotation. That means it provides two translational reaction forces (one horizontal, one vertical) and a bending moment to resist rotation. So the correct description is two reactions plus one moment. The other options miss either a translational reaction or the moment, which would not match the way a fixed support constrains the structure.

A built-in, fixed support prevents movement in both horizontal and vertical directions and also stops rotation. That means it provides two translational reaction forces (one horizontal, one vertical) and a bending moment to resist rotation. So the correct description is two reactions plus one moment. The other options miss either a translational reaction or the moment, which would not match the way a fixed support constrains the structure.