21. An -section 240 mm x 120 mm x 20 mm is used as 6 m long column with both ends fixed. What is the crippling load for the column? Take Young's modulus for the joist as 200 GPa. (a) 1293.5 KN (b) 1292.5 kN (c) 1294.5 kN (d) 1295.5 kN 25 22. A hollow column of 200 mm external diameter and 160 mm internal diameter is used as a column of 4.5m length. Calculate the Rankine's crippling load when the column is fixed at both ends. Take allowable stress as 350 MPa and Rankine's constant as 1/1600. (a) 2.53 kN (b) 3.23 kN (c) 2.23 KN (d) 3.53 kN 23. A hollow cast iron 5 m long column with both ends fixed is required for support a load of 1000 KN. If the external diameter of the column is 250 mm, find its