The hoop stress in a riveted cylindrical shell of diameter (d), thickness (t) and subjected to an internal pressure (p) is (where $$\eta $$ = Efficiency of the riveted joint)

A. Single B. Double C. Both A and B D. None of these

A. Equal to B. Less than C. Greater than D. None of these

A. $$\frac{{{\text{w}}l}}{6}$$ B. $$\frac{{{\text{w}}l}}{3}$$ C. $${\text{w}}l$$ D. $$\frac{{2{\text{w}}l}}{3}$$

A. Short columns B. Long columns C. Weak columns D. Medium columns