Q1 of 32 Page 250

A joker’s cap is in the form of right circular cone whose base radius is 7 cm and height is 24 cm. Find the area of the sheet required to make 10 such caps.


Given that, the radius of cone(r) is 7 cm and height(h) is


24 cm.


And, Surface area of cone is - πrl


Also, slant height(l) = √ r2 + h2


⇒ l = √ 72 + 242


⇒ l = √ 49 + 576


⇒ l = √ 625


⇒ l = 25


⇒ Surface area of joker’s cap


= 550cm2


⇒ ∴ the area of the sheet required to make 10 such caps


= 550 × 10 cm2


= 5500 cm2


More from this chapter

All 32 →
2

A sports company was ordered 100 paper cylinders for packing shuttle cocks. The required dimensions of the cylinder are 35 cm length/height and its radius is 7 cm. Find the required area of thick paper sheet needed to make 100 cylinders?

 3

Find the volume of right circular cone with radius 6 cm. and height 7 cm.

 4

The lateral surface area of a cylinder is equal to the curved surface area of a cone. If their bases be the same, find the ratio of the height of the cylinder to the slant height of the cone.

 5

A self-help group wants to manufacture joker’s caps of 3 cm. radius and 4 cm height. If the available paper sheet is then how many caps can be manufactured from that paper sheet?