Question:
If the height of a cylinder becomes 1/4 of the original height and the radius is doubled, then which of the following will be true?
(a) Total surface area of the cylinder will be doubled.
(b) Total surface area of the cylinder will remain unchanged.
(c) Total surface of the cylinder will be halved.
(d) None of the above.
Solution:
The correct answer is option (d) None of the above.
Explanation:
We know that, the total surface area of a cylinder is 2π r(h + r), when the radius is “r” and height is “h”.
If the radius is 2r and the height is (1/4)h, then the total surface area becomes,
= 2π (2r) ((1/4)h + 2r)
= 4 πr [(h+8r)/4]
= πr (h+8r)