Question

A hollow cylinder open at both ends is made of steel 2cm thick. What will be the volume of steel used in making the cylinder, if the external diameter is 24cm and the length of cylinder is 55cm?

• A. 7598.8 cu.cm
• B. 8500 cu.cm
• C. 11234 cu.cm
• D. 15197.6 cu.cm

Answer 1

The correct option is

A

7598.8 cu.cm

External radius R = 12 cm

Internal radius r = 12 cm - 2cm = 10 cm

Volume of hellow cylinder = 2πh($R^2$ - $r^2$)

Required volume of steel = 2 $\times$ 3.14 $\times$ 55 $\times$ (${12}^2$ - ${10}^2$)

Hence, required volume of steel = 15197.6 cu. cm