Question

The total surface area of a hemisphere is 462 cm2 .The diameter of this hemisphere is:

• A. 28 cm
• B. 21 cm
• C. 7 cm
• D. 14 cm

Answer 1

Answer:

D. 14 cm

Solution:

Given:

The total surface area of a hemisphere is 462 cm² 

Formula Used:

The total surface area of a hemisphere = 3πr²

Diameter = 2r 

Where, r = radius of a hemisphere

Calculation:

Here, the total surface area of a hemisphere = 462 

⇒ 3πr² = 462 

⇒ $3\times{\frac{22}{7}}\times{r^2}=462$

⇒ r² = 49

⇒ r = 7 cm 

Diameter = 2r = 2 × 7 = 14 cm 

Hence, the diameter of the hemisphere is 14 cm .