Surface Areas and Volumes
CBSE 2026 Board Exam Set 1 (Code 30/7/1)
CBSE_BOARD_PYQ_2026_30_7_1
Grade 10
Question:
[Section A]
If the slant height of a cone is $5$ cm and radius of its base is $4$ cm, its curved surface area is:
(A) $20\pi$ cm$^2$
(B) $12\pi$ cm$^2$
(C) $16\pi$ cm$^2$
(D) $25\pi$ cm$^2$
Step-by-Step Solution
Key Concept: CSA of cone $= \pi r l = \pi (4)(5) = 20\pi$ cm$^2$.
Sol. (A) $20\pi$ cm$^2$. [1.0 Mark]
Correct Answer: (A) $20\pi$ cm$^2$
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