Question

If a sheet of paper of length 10 cm and breadth 5 cm is rolled along its length to form a cylinder, then find the volume of the cylinder. Take $\pi$ = 3.14.

• A. 39.809 $c{m}^3$​
• B. 38.908 $c{m}^3$​
• C. 39.5 $c{m}^3$​
• D. 39.09$c{m}^2$

Answer 1

The correct option is A

39.809 $c{m}^3$​

When a rectangle is rolled across the length, then the height of cylinder formed will be same as the width of the rectangle, i.e., 5 cm and the length of the rectangle will be the circumference of the circular base of the cylinder.
$⟹2\pi r=10$
$\Rightarrow$ r = $\frac{5}{\pi }$
$\therefore$ Volume of cylinder $=\pi r^{2}h$
$=3.14\times \frac{25}{{3.14}^2}\times 5$
$=39.809{\text{cm}}^3$