Viva Voce: Volume of a Cone | Lab Manuals for Class 10 PDF Download

Q.1. Ratio of volumes of two cones having, the same base radius is 9:25, then what is the ratio of their heights ?

9:25.

Q.2. Base radii of two cones of same heights are in the ratio 3:5. Find the ratio of their volumes ?

9:25.

Q.3. Can we say that volume of a cone is 3 times the volume of a cylinder ?

No.

Q.4. Radii of two cones of same heights are in the ratio 2:5. Find the ratio of their volume.

4:25.

Q.5. What is the ratio of the volume of a cylinder to volume of a cone of same height and same base ?

3:1.

Q.6. Two cones have their heights in the ratio 1 : 3 and the radii of their bases are in the ratio 3:1. What is the ratio of their volumes ?

3:1.

Q.7. What is the volume of a cone ?

= 1/3 πr²h

Q.8. Radius of a cone is halved and height is doubled. What effect will be on its volume ?

It will be half of original

Q.9. Find the volume of the right circular cone with radius 6 cm, height 7 cm

Volume of a cone of base radius r, and height h, = 1/3πr²h
Radius of the cone, r = 6 cm
Height of the cone, h = 7 cm
Volume of the cone = 1/3πr²h
= 1/3 × 22/7 × 6 cm × 6 cm × 7 cm
= 264 cm³ 

Q.10. A heap of wheat is in the form of a cone whose diameter is 10.5 m and height is 3 m, then volume is

Volume of a cone of base radius, 'r' and height, 'h' = 1/3πr²h  
Curved surface area of the cone having a base radius, 'r' and slant height, 'l' = πrl
Slant height of the cone, l = √r² + h² 
Diameter of the conical heap, d = 10.5 m
Radius of the conical heap, r = 10.5/2 m = 5.25 m
Height of the conical heap, h = 3 m
Volume of the conical heap = 1/3πr²h
= 1/3 × 22/7 × 5.25 m × 5.25 m × 3 m
= 86.625 m³