When a bar of length '$$l$$' and diameter 'd' is rigidly fixed at the upper end and hanging freely, then the total elongation produced in the bar due to its own weight is (where w = Weight per unit volume of the bar)

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