If the radius of a cylinder is tripled but its curved surface area is

1.	If the radius of a cylinder is tripled but its curved surface area is unchanged, then its height will be(a) tripled (b) constant (c) one sixth (d) one third
Answer» The correct answer is option (d) one third Explanation: We know that the curved surface area of a cylinder is 2πrh, when the radius is “r” and height is “h”. Let “H” be the new height. When the radius of a cylinder is tripled, then the CSA of a cylinder becomes, CSA = 2π (3r) H CSA = 6πr. H Now, compare the CSA of the cylinder to find the height 6πrH = 2πrh H = 2πrh / 6πr H = (1/3)h Hence, the new height of the cylinder is one-third of the original height.

If the radius of a cylinder is tripled but its curved surface area is unchanged, then its height will be(a) tripled (b) constant (c) one sixth (d) one third

Answer»

The correct answer is option (d) one third

Explanation:

We know that the curved surface area of a cylinder is 2πrh, when the radius is “r” and height is “h”.

Let “H” be the new height.

When the radius of a cylinder is tripled, then the CSA of a cylinder becomes,

CSA = 2π (3r) H

CSA = 6πr. H

Now, compare the CSA of the cylinder to find the height

6πrH = 2πrh

H = 2πrh / 6πr

H = (1/3)h

Hence, the new height of the cylinder is one-third of the original height.