• # question_answer A metal pipe of 1 m diameter contains a fluid having a pressure of $10\,\,\text{kgf/c}{{\text{m}}^{\text{2}}}\text{.}$ If the permissible tensile stress in the metal is $200\,\,\text{kgf/c}{{\text{m}}^{\text{2}}}$ then the thickness of the metal required for making the pipe would be: A) 5 mm               B) 10 mmC) 20 mm             D) 25 mm

${{\sigma }_{\theta }}=\frac{pd}{2t}$ $t=\frac{10\times 100}{2\times 200}=2.5\,\,cm\,\,\,or\,\,\,25\,\,mm$