A bar of square section of area a^{2} is held such that its one of its diagonals is vertical. The maximum shear stress will develop at a depth h where h is

A steel rod of sectional area 250 sq. mm connects two parallel walls 5 m apart. The nuts at the ends were tightened when the rod was heated to 100°C. If α_{steel} = 0.000012/C°, E_{steel} = 0.2 MN/mm^{2}, the tensile force developed at a temperature of 50°C, is