Torsion results from applying torque and causes which deformation?

• A. Rotation without deformation.
• B. Twisting of the object.
• C. Sagging due to gravity.
• D. Buckling.

Answer: (B)

Torsion produces twisting deformation along the length of the object. When torque is applied about an axis, the cross-sections rotate relative to one another, creating shear stresses that cause the material to twist rather than just spin as a rigid body. In simple terms, the object ends up twisted along its length, with the angle of twist depending on the torque, length, and material properties (G and the polar moment of area J). This is different from rotation without deformation (which would be rigid-body spin), sagging due to gravity (bending under load), or buckling (l lateral deflection under compression). Hence the deformation is twisting of the object.