Correct Answer - Option 1 : 2π(R+r)(R+h-r)
Given:
Height = h, R = external radius and r = internal radius
Formula:
Total surface area of cylinder = lateral surface area + area of bases
Calculation:
Lateral surface area of hollow cylinder = 2πh(R + r)
Area of bases = 2π(R2 - r2)
Total surface area of hollow cylinder =
⇒ 2πh(R + r) + 2π(R2 - r2)
⇒ 2πh(R + r) + 2π(R + r)(R - r)
⇒ 2π(R + r)(h + R - r)
⇒ 2π(R + r)(R + h - r)
∴ Total surface area of hollow cylinder = 2π(R + r)(R + h - r)