Question

A hemispherical bowl is made of steel, 0.25 cm thick.The inner radius of the bowl is 5 cm. Find the outer curved surface area of the bowl. $[Assume\pi =\frac{22}{7}]$

• A. $173.25c{m}^2$
• B. $183.25c{m}^2$
• C. $273.25c{m}^2$
• D. $179.25c{m}^2$

Answer 1

The correct option is A

$173.25c{m}^2$

Inner radius of the hemispherical bowl = 5 cm

Thickness of the bowl = 0.25 cm

$\therefore$ Outer radius (r) of the hemispherical bowl = (5 + 0.25) cm

= 5.25 cm

Outer CSA of hemispherical bowl $=2\pi r^2$

$=2\times \frac{22}{7}\times (5.25cm{)}^2=173.25c{m}^2$