The volume of a solid right circular cylinder of height 8 cm is 392π

1.	The volume of a solid right circular cylinder of height 8 cm is 392π cm3. Its curved surface area (in cm2) is:1. 96π 2. 161π3. 112π4. 210π
Answer» Correct Answer - Option 3 : 112π Given: Volume of the cylinder = 392π cm³ Height of the cylinder (h) = 8 cm Concept used: Volume of the right circular cylinder = π × r² × h Curved surface area of the right circular cylinder = 2 × π × r × h Calculation: Let the radius of the right circular cylinder be r. π × r² × h = 392π ⇒ r² × 8 = (392π)/π ⇒ r² = 392/8 ⇒ r² = 49 ⇒ r = 7 Curved surface area = 2 × π × 7 × 8 ⇒ 112π ∴ The curved surface area of the right circular cylinder (in cm2) is 112π.

The volume of a solid right circular cylinder of height 8 cm is 392π cm3. Its curved surface area (in cm2) is:1. 96π 2. 161π3. 112π4. 210π

Answer» Correct Answer - Option 3 : 112π

Given:
Volume of the cylinder = 392π cm³
Height of the cylinder (h) = 8 cm

Concept used:
Volume of the right circular cylinder = π × r² × h
Curved surface area of the right circular cylinder = 2 × π × r × h

Calculation:
Let the radius of the right circular cylinder be r.
π × r² × h = 392π
⇒ r² × 8 = (392π)/π
⇒ r² = 392/8
⇒ r² = 49
⇒ r = 7
Curved surface area = 2 × π × 7 × 8
⇒ 112π
∴ The curved surface area of the right circular cylinder (in cm2) is 112π.

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