Question

Find the capacity in litres of a conical vessel with radius $7cm$, slant height $25cm$

• A. $1.232l$
• B. $2.232l$
• C. $1.322l$
• D. $1.132l$

Answer 1

The correct option is A $1.232l$

Volume of a cone $=\frac{1}{3}\pi r^{2}h$

For a cone, $l=\sqrt{h^2+r^2}$ where, $l$ is the slant height.

Hence, $25=\sqrt{h^2+7^2}$

$625=h^2+49$

$h^2=576$

$h=24cm$

Hence, volume of this cone $=\frac{1}{3}\times \frac{22}{7}\times 7^2\times 24=1232{cm}^3=\frac{1232}{1000}=1.232$ litres.