If a conical vessel has a radius of 4 cm and volume of 16π cm3 , then its curved surface area is
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Correct answer: D
Explanation
The Correct answer is option 4 i.e. 20π cm2
Given that
A conical vessel has a radius (r) = 4 cm
The volume of the vessel = 16π cm3
Formula used
The volume of a cone = ⅓ 𝜋r2h
CSA of cone = πrL
Calculation
⅓ 𝜋r2h = 16π
(1/3) × 42 × h = 16
h = 3cm
As we know,
L = √(h2 + r2)
L = √(32 + 42) = 5 cm
Hence, CSA of cone = πrL= 5 × 4 π = 20π cm2