Deflection is the response of a structural element to which of the following?

• A. external stresses and its own weight causing bending
• B. resistance to shear along a plane
• C. torsion due to twisting
• D. axial compression along the member length

Answer: (A)

Deflection is the transverse displacement of a structural element under loading due to bending moments created by external loads and the member’s own weight. When a beam carries external forces and its weight, bending moments develop along its length, causing the member to bend and move from its original position. This movement is what we refer to as deflection. It’s not primarily about resisting shear along a plane, twisting from torque, or shortening along the axis from compression—that would describe shear deformation, torsion, and axial shortening, respectively. Deflection specifically captures the bending-induced displacement that results from those external stresses and the self-weight.