Q. 123.8( 4 Votes )

# If the radius of the cylinder is tripled but its curved surface area is unchanged, then its height will be

A. triple

B. constant

C. one-sixth

D. one-third

Answer :

Let H be the new height.

Curved surface area of a cylinder with radius r and height h = 2πrh

Now, according to the question, radius is tripled

Then,

Curved surface area = 2π × 3r × h = 2πrh

6πrh = 2πrh

H =

H = h

Hence ,the new height will be of the original height.

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If the height of a cylinder becomes of the original height and the radius is doubled, then which of the following will be true?

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