Surface Area of Sphere
Surface Area of Sphere
Surface area of a Sphere: The surface area of sphere of radius r is given by
Illustration: Find the surface area of sphere of radius 7cm.
Solution: We known that the surface area S of a sphere of radius r is given by
with
Given: r = 7cm
Illustration: The diameter of the moon is approximately one fourth of the diameter of the Earth. Find the ratio of their surface areas.
Solution: Let the Moon's diameter = d
Given: The diameter of the moon is approximately one fourth of the diameter of the Earth
Hence, Earth's diameter = 4d
Let and
denote the surface areas of Moon and Earth respectively.. Then,
Hence the ratio of their surface areas = 1 : 16
The surface area of sphere of diameter 21 cm is ________________ . | |||
| Right Option : D | |||
| View Explanation | |||
The surface area of a sphere is 1056 sq cm, its diameter is __________________ . | |||
| Right Option : C | |||
| View Explanation | |||
The surface area of a sphere is 5544 sq cm, its diameter is _________________. | |||
| Right Option : C | |||
| View Explanation | |||
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