SarkariPYQ

SSC GD 2023 PYQ — Question 50

SSC GD Constable (English) - 13 Jan 2023 - Shift 4 • Quantitative Aptitude • Q50

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If the curved surface area of a sphere with radius R1 unit is the same as the total surface area of another hemisphere with radius R2 , then the R2 is:

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Correct answer: A

Explanation

The correct answer is option 1 i.e. 

Curved surface area of a sphere with radius R1 = 4π(R1)2

Total surface area of a hemisphere with radius R2 = 3π(R2)2

According to the question -

Curved surface area of a sphere with radius R1 = Total surface area of a hemisphere with radius R2

4π(R1)2 = 3π(R2)2

R22 = 4(R1)2/3

R2 = 2(R1)/√3