Surface Area of Hemisphere formula

A circular shaped ball with a diameter or radius is called a sphere.A diameter which is a straight line through the center of a sphere and with the end points on the boundary is called its diameter.

The section of the sphere by the plane is called a hemisphere. Let’s see how to find the area of Hemisphere.

Formula of Surface area of Hemisphere.

Total Surface area of Sphere (TSA) = 4πr2

Curved Surface area of Hemisphere(CSA) = 2πr2

Total Surface area (TSA) = 3πr2

Surface area of Hemisphere Formula Examples

Question: The radius of a red balloon increases from 6cm to 12 cm when the air is pumped into it. Calculate the ratios of the surface areas of the balloon in both the cases.

Solution: Hemisphere 1 – r = 6cm

Hemisphere 2 – r = 12 cm

TSA – 1 = 3πr2

= 3π(6)2

TSA – 2 =3π(12)2

Let’s find the ratio: TSA1 /TSA2, = ½

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Practise This Question

The noble gases have closed-shell electronic configuration and are monoatomic gases used normal conditions. The low boiling points of the lighter noble gases are due to weak dispersion forces between the atoms and the absence of other interatomic interactions.

The direct reaction of xenon with fluorine leads to a series of compounds with oxidation number +2, +4 and +6. XeF4 reacts violently with water to give XeO3. The compounds of xenon exhibit rich stereochemistry and their geometries can be deduced considering the total number of electron pairs in the valence shell.

XeF4 and XeF6 are expected to be