Q. In a circle, if radius is doubled, what happens to the area?

Correct Answer: (D) It quadruples

Explanation:

The area of a circle is given by the formula:

Area = π r^2

Where r is the radius of the circle. If the radius is doubled, the new radius becomes 2r. Substituting this into the formula for the area:

New Area = π (2r)^2 = π (4r^2) = 4 × (π r^2)

This shows that the new area is 4 times the original area. Therefore, when the radius is doubled, the area quadruples.

Thus, the correct answer is (D) It quadruples.