Question

The ratio of diameter to height of a Borosil cylindrical glass is 3 : 5. If the actual diameter of the glass is 6 cm, then the curved surface area of the glass is ______.

विकल्प

• 120π

• 60π

• 30π

• 18π

Answer 1

The ratio of diameter to height of a Borosil cylindrical glass is 3 : 5. If the actual diameter of the glass is 6 cm, then the curved surface area of the glass is 60π.

Explanation:

Given diameter = 6 cm → radius r = 3 cm.

Ratio diameter : height = 3 : 5 

⇒ If diameter = 6 (i.e. 3 × 2) then height = 5 × 2 = 10 cm.

Curved surface area (CSA) of a cylinder = 2πrh

= 2π × 3 × 10

= 60π cm²