Question

Assertion (A): The area of canvas cloth required to just cover a heap of rice in the form of a cone of diameter 14 m and height 24 m is $175\pi$ sq.m.
Reason (R): The curved surface area of a cone of radius $r$ and slant height $l$ is $\pi r l$.

• A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
• B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A)
• C. Assertion (A) is true, but Reason (R) is false.
• D. Assertion (A) is false, but Reason (R) is true.

Answer 1

The Correct Option is A

For a cone:
\[Curved Surface Area (CSA) = \pi r l\]
Given: $r = \frac{\text{Diameter}}{2} = 7 \, \text{m}$, $h = 24 \, \text{m}$, and $l = \sqrt{r^2 + h^2} = \sqrt{7^2 + 24^2} = \sqrt{49 + 576} = 25 \, m$.
\[CSA = \pi r l = \pi \times 7 \times 25 = 175\pi \, sq.m\]
Both (A) and (R) are true, and (R) explains (A).