Q. 4 Select right answer. A rotating steel flat disk has 200 mm inner diameter and 300 mm outer diameter. If the maximum shear stress is to not exceed 90 MPa the allowable speed in rpm is around 10180 rpm Q. 5 Select right answer. A thin steel disk of inner and outer radii 200 and 300 mm respectively rotates at 100 rad/sec. The maximum radial stress is O.32 MPa Q.6 Select right answer. A thin steel disk of inner and outer radii 200 and 300 mm respectively rotates at 100 rad/sec. The displacement at the inner edge is around 6.34 microns Q. 7 Select right answer. A thin steel disk of inner and outer radii 200 and 300 mm respectively rotates at 100 rad/sec. The radial strain at the outer edge is 5.7 micr-strain Q. 8 Select right answer. A gun barrel is formed by shrinking a tube of 300 mm external diameter and 200 internal diameters upon another tube of 126 mm internal diameter. After shrinkage, the radial pressure at the common surface is 10 MPa. The hoop stress at the inner surface of the outer tube is 26 MPa