Question

The curved surface of a circular cylinder of height 'h' and the curved surface area of the cone of slant height 2 'h' having the same circular base are in the ratio of

• A. 1 : 2
• B. 2 : 1
• C. 1 : 1
• D. 1 : 3

Answer 1

The correct option is C 1 : 1

Let the base radius of cone and circular cylinder is r and height of circular cylinder is h and height of cone 2h

Then Curved surface area of circular cylinder =$2\pi rh$

And curved surface area of cone=$\pi r\left(2h\right)=2\pi rh$

So ratio of Curved surface area of circular cylinder : curved surface area of cone :: $2\pi r\left(h\right)=2\pi rh$ : $2\pi rh$=1:1