2015 · Q59
Consider the following statements :
- 1If the height of a cylinder isdoubled, the area of the curved surface is doubled.
- 2If the radius of a hemispherical solid is doubled, its total surface area becomes fourfold.
Which of the above statements is/are correct ?
Elementary MathematicsGeometry: Lines, Angles and Triangles
- A1 only
- B2 only
- CBoth 1 and 2
- DNeither 1 nor 2
Explanation
Curved surface 2*pi*r*h doubles with h (statement 1 true); solid-hemisphere total surface 3*pi*r^2 quadruples with r (statement 2 true). Hence option (c).