Frustum of a Cone

Author:Neha Tyagi & Amit Rastogi
10th CBSE
IMPORTANT

Frustum of a Cone: Overview

In this topic, we will learn about a solid, which is part of a right circular cone when a plane parallel to the base of the cone cuts it. Such solid is called a frustum. Examples are given for a better understanding.

Important Questions on Frustum of a Cone

EASY
IMPORTANT

An open metallic bucket is in the shape of a frustum of a cone, mounted on a hollow cylindrical base made of the same metallic sheet. The surface area of the metallic sheet used is equal to the curved surface area of the frustum of a cone + area of the circular base + curved surface area of the cylinder.

HARD
IMPORTANT

The curved surface area of a cone is πlr1+r2, where l=h2+r1+r22  r1 and r2 are the radius of the two ends of the frustum and h is the vertical height.

HARD
IMPORTANT

The volume of the frustum of a cone is 13πhr12+r22-r1r2, where h is vertical of frustum and r1,r2 are the radius of ends.

HARD
IMPORTANT

A milk container of height 16 cm is made of metal sheet in the form of a frustum of a cone with radii of its lower and upper ends as 8 cm and 20 cm, respectively. Find the cost of milk at the rate of 22 per L which the container can hold.

HARD
IMPORTANT

A cone of radius 8 cm and height 12 cm is divided into two parts by a plane through the mid-point of its axis parallel to its base. Find the ratio of the volumes of two parts.

MEDIUM
IMPORTANT

A bucket is in the form of a frustum of a cone and holds 28.490 L of water. The radius of the top and bottom are 28 cm and 21 cm, respectively. Find the height of the bucket.

 

MEDIUM
IMPORTANT

The diameters of the two circular ends of the bucket are 44 cm and 24 cm. The height of the bucket is 35 cm. The capacity of the bucket is  

EASY
IMPORTANT

In a right circular cone, the cross-section made by a plane parallel to the base is a 

EASY
IMPORTANT

A cone is cut through a plane parallel to its base and then the cone that is formed on one side of that plane is removed. The new part that is left over on the other side of the plane is called

EASY
IMPORTANT

The shape of a glass tumbler is usually in the form of 

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