Multiple choice

A sphere of a radius of 10cm is cut into two pieces. Find how much percentage increase in total surface area?

  1. 50%

  2. 40%

  3. 82%

  4. 32%
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A Correct answer
Explanation

When a sphere of radius r is cut into two pieces, two new circular faces are exposed, each with area πr². Original surface area = 4πr². New total surface area = 4πr² + 2πr² = 6πr². Percentage increase = (6πr² - 4πr²)/4πr² × 100 = 2πr²/4πr² × 100 = 50%.

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