The curved surface area of a right circular cylinder of base radius r is obtained by multiplying its volume:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → \(\displaystyle\frac{2}{r}\)
Both formulas contain \(\pi rh\), so the factor that turns the volume into the curved surface area is their ratio.
Curved surface area \(=2\pi rh\), volume \(=\pi r^2h\)
\(\displaystyle\frac{2\pi rh}{\pi r^2h}=\frac{2}{r}\)
So curved surface area \(=\text{volume}\times\displaystyle\frac{2}{r}\)