PPSC CE SOM_SFD-Columns ,spring and prsuure vessels

Which of the following statements are correct about thin spherical shells being used as pressure vehicles?

i. Hoop stress is the same as for a cylindrical shell with the same diameter and thickness subjected to same pressure.

ii. All the planes on the surface are principal planes

iii. Maximum in plane shear stress is zero

iv. Volumetric strain is three times the hoop strain

Which of the following statements are true about stresses in thick cylindrical pressure vessels under the effect of internal pressure?

i. Hoop stress is maximum inside

ii. Hoop stress is zero at the outside surface

iii. Hoop stress is tensile in nature

A spherical shell of diameter 200 mm and thickness 10mm made of mild steel is subjected to an internal pressure of 100MPa. Find out the change in volume of the shell (in cm³). Use E.

Lame’s lines are used for

A circular pipe of 100 mm diameter and 5 mm thickness is 500 m under sea water. If the pressure of liquid inside the pipe is 10N/mm², what is the maximum stress induced in the pipe walls? Assume the density of sea water to be 1033 kg/m³.

Which of the following stresses remain constant over the thickness for both thin and thick shells?

i. Longitudinal

ii. Hoop

iii. Radial