In NCERT Solution For Class 10, Maths, Chapter 13, Surface Areas And Volumes, Exercise 13.4, we will discuss questions related Frustum of a Cone. Frustum may be defined as when we slice (or cut) through it with a plane parallel to its base and remove the cone that is formed on one side of that plane, the part that is now left over on the other side of the plane is called a frustum of the cone. Ex. 13.4, chapter 13 has total five questions to discuss.
Class 10, Maths, Chapter 13, Exercise 13.4 Solutions
Take π = $\frac{22}{7}$, unless state otherwise.
Q.1. A drinking glass is in the shape of a frustum of a cone of height 14 cm. The diameters of its two circular ends are 4 cm and 2 cm. Find the capacity of the glass.
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Q.2. The slant height of a frustum of a cone is 4 cm and the perimeters (circumference) of its circular ends are 18 cm and 6 cm. Find the curved surface area of the frustum.
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Q.3. A fez, the cap used by the Turks, is shaped like the frustum of a cone. If its radius on the open side is 10 cm, radius at the upper base is 4 cm and its slant height is 15 cm, find the area of material used for making it.
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Q.4. A container, opened from the top and made up of a metal sheet, is in the form of a frustum of a cone of height 16 cm with radii of its lower and upper ends as 8 cm and 20 cm, respectively. Find the cost of the milk which can completely fill the container, at the rate of ₹ 20 per litre. Also find the cost of metal sheet used to make the container, if it costs ₹8 per 100 cm2. (Take π = 3.14)
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Q.5. A metallic right circular cone 20 cm high and whose vertical angle is 60° is cut into two parts at the middle of its height by a plane parallel to its base. If the frustum so obtained be drawn into a wire of diameter cm. find the length of the wire.
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