1. The circumference of the base of 9 m high conical tent is 44 m. Find the volume of the air contained in it.
a) 390 m3 b) 462 m3 c) 480 m3 d) None of these
Sol: Circumference of the base of the cone = 2πr = 44 m
⇒ r = 7 m, height = 9 m
∴ Volume of air contained in the conical tent
= 462 m3
2. If the radius of the base of a right circular cone is 3r and height is equal to the radius of the base, then its volume is equal to.....
3. A cylinder and a cone stands on the same base and have equal height. It is also found that area of their curved surfaces are equal. Find the ratio of their base radius and their height.
a) 1 : 1 b) 1 : 3 c) 1 : √3 d) √3 : 1
Sol: Let the radius of their base be ‘r’ and the height be h.
4. If 800 cm3 of water is poured into an inverted conical vessel, the depth of water is 6 cm. How much more water should be added to it to make the depth 9 cm?
a) 2700 cm3 b) 1900 cm3 c) 1700 cm3 d) 400 cm3
Additional water = 2700 - 800 = 1900 cm3
5. A child reshapes a cone made up of clay having height 24 cm and radius 6 cm into a sphere. The radius (in cm) of the sphere is
a) 6 b) 12 c) 24 d) 48
⇒ r = 6 cm