Direction: Write True or False and justify your answer in each of the following :
If the radius of a cylinder is doubled and its curved surface area is not changed, the height must be halved.
Answer : True
We know that curved surface area of the cylinder is given as
(where r is the radius and h is height)
Given that the radius of a cylinder is doubled and it’s curved surface area is not changed
For new cylinder,
New radius
Let new height be
Now, according to the question –
Hence the height is halved.
Thus, the statement is true.