Correct Answer - Option 2 : 250

__Concept:__

For thin cylindrical vessel:

Hoop stress, \({\sigma _h} = \frac{{pd}}{{2t}}\)

Longitudinal stress, \({\sigma _L} = \frac{{pd}}{{4t}}\)

__Calculation:__

**Given:**

r = 500 mm, d = 1000 mm, p = 5 MPa = 5 N/mm2, t = 10 mm

\(\sigma_h=\frac{{pd}}{{2t}} = \frac{{5 \times 1000}}{{2 \times 10}} = 250\;N/m{m^2}\)

For thin spherical vessel:

Hoop stress/Longitudinal stress:

\({\sigma _h} = {\sigma _L} = \frac{{pd}}{{4t}}\)