Question

The curved surface area of a cylindrical rod is 264 cm² and volume is 924 cm³. Then find the Ratio of height and radius? (Use π = 22/7)
1. 6 : 7
2. 7 : 6
3. 7 : 3
4. 3 : 7

Answer 1

Correct Answer - Option 1 : 6 : 7

Given:

Curved surface area of cylindrical rod = 264 cm²

Volume of cylindrical rod = 924 cm³

Formula Used:

Curved surface area of cylinder = 2πrh, r = Radius and  h = height of cylinder

Volume of cylinder = πr2h

Calculation:

Let the radius of the base of the cylinder be r and height be h

2πrh = 264 cm²

⇒ πrh = 264/2 cm²

⇒ πrh = 132 cm²      (i)

πr2h = 924 cm³

Putting value of πrh from equation (i)

⇒ 132r cm² = 924 cm³

⇒ r = 924/132 cm

⇒ r = 7 cm

Putting r = 7 in equation (i)

⇒ 22/7 × 7 × h = 132 

⇒ h = 132/22 cm

⇒ h = 6 cm 

Ratio of h and r = 6 : 7

∴ The ratio of height and radius of cylinder is 6 : 7