A steel rod, 100 mm long is held between two rigid supports. It is heated by 20°C. If the coefficient of thermal expansion of the material of the rod is 15 x 10-6 /° C and modulus of elasticity is 200 x 103 MN/m2, what is the stress in the rod ?
Consider for following statements : In an under-reinforced concrete beam, 1. actual depth of neutral axis is less than the critical depth of neutral axis. 2. concrete reaches ultimate stress prior to steel reaching the ultimate stress. 3. moment of resistance is less than that of balanced sections. 4. lever arm of resisting couple is less than that of balanced sections. Which of the statements given above are correct ?