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If the radius of the base of a right circular cylinder is halved, keeping the height the same, then find the ratio of the volume of the cylinder thus obtained to the volume of original cylinder? |
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Answer» Let the radius of the base of original cylinder is r. And the height of the original cylinder is h. ∴ The volume of the original cylinder is \(\pi\)r2ℎ. Given that radius of base of reduced cylinder is half of radius of original cylinder and height will be same. ∴ The radius of reduced cylinder is \(\frac{r}2\) And the height of the reduced cylinder is h. ∴ The volume of the reduced cylinder is \(\pi\)\((\frac{r}{2})^2\) ℎ. Now, the ratio of the volume of reduced cylinder and the volume of original cylinder is \(\frac{Volume\,of\,reduced\,cylinder}{Volume\,of\,original\,cylinder}\) = \(\frac{\pi(\frac{r}2)^2h}{\pi{r}^2h}\) = \(\frac{\pi{r}^2h}{4\pi{r}^2h}\) = \(\frac{1}4\). Hence, the required ratio is 1 : 4. |
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