In flexibility method the unknown quantities are ----------------- whereas in stiffness method the unknown quantities are --------------

Flexibility of a structure may be defined as the displacement caused by ----------------- force and stiffness of a structure may be defined as the force required for ----------------- displacement

Which of the following statements is true with regard to the flexibility method of analysis.

A single bay portal frame of height $$'h'$$ fixed at the base is subjected to a horizontal displacement $$'\delta '$$ at the top. The base moments developed is proportional to _____, where $$'{\rm I}'$$ is the moment of inertia of the cross section.