A company manufactures hemispherical brass bells of radius 2 cm. If polishing costs ₹0.75 per square cm, find the cost of polishing the outer surface of one bell.
Show answer & explanation
Correct answer: A
Explanation
Given:
Radius (r) = 2 cm
Polishing cost = ₹0.75 per cm²
By formula:
Curved surface area of hemisphere = 2πr²
Area = 2 × π × 2² = 8π
= 8 × 22/7 = 176/7 cm²
Total cost = (176/7) × 0.75 = ₹18.85