81). What is the volume of a cone having a base of radius 10 cm and height 21 cm?
| A). \( \Large 2200 cm^{3} \) |
| B). \( \Large 3000 cm^{3} \) |
| C). \( \Large 5600 cm^{3} \) |
| D). \( \Large 6600 cm^{3} \) |
|
82). The diameter of the base of a cone is 6 cm and altitude is 4 cm. What is the approximate curved surface area of the Cone?
| A). \( \Large 45 cm^{2} \) |
| B). \( \Large 47 cm^{2} \) |
| C). \( \Large 49 cm^{2} \) |
| D). \( \Large 51 cm^{2} \) |
|
83). If the volume of a right circular cone of height 9 cm is \( \Large 48 \pi cm^{3} \), then find the diameter of its base.
| A). 8 cm |
| B). 4 cm |
| C). 7 cm |
| D). 11 cm |
|
84). Shantanu's cap is in the form of a right circular cone of base radius 7 cm and height 24 cm. Find the area of the sheet required to make 5 such caps.
| A). 5000 sq cm |
| B). 2750 sq cm |
| C). 3000 sq cm |
| D). 2700 sq cm |
|
85). The diameter of a right circular cone is 14 m, while its slant height is 9 cm. Find the volume of the cone.
| A). \( \Large \frac{49 \pi \sqrt{32}}{3}\ m^{3} \) |
| B). \( \Large \frac{50 \pi \sqrt{32}}{3}\ m^{3} \) |
| C). \( \Large \frac{3}{49 \pi \sqrt{32}}\ m^{3} \) |
| D). \( \Large \frac{ \pi \sqrt{32}}{9}\ m^{3} \) |
|
86). The frustum of a right circular cone has the diameters of base 10 cm. of top 6 cm and a height of 5 cm. Find its slant height.
| A). \( \Large \sqrt{29} \)cm |
| B). \( \Large 3\sqrt{3} \)cm |
| C). \( \Large \sqrt{13} \)cm |
| D). \( \Large 4\sqrt{3} \)cm |
|
87). The frustum of a right circular cone has the radii of base 4 cm, of the top 2 cm and a height of 6 cm. Find the volume of the frustum.
| A). \( \Large 115 cm^{3} \) |
| B). \( \Large 156 cm^{3} \) |
| C). \( \Large 185 cm^{3} \) |
| D). \( \Large 176 cm^{3} \) |
|
88). If the ratio of volumes of two cones is 2 : 3 and the ratio of the radii of their bases is 1 : 2, then the ratio of their heights will be
| A). 3 : 8 |
| B). 8 : 3 |
| C). 9 : 2 |
| D). 8 : 1 |
|
89). The ratio of the radius and height of a cone is 5 : 12. Its volume is \( \Large 314\frac{2}{7} cm^{3} \). Its slant height is
| A). 18 cm |
| B). 13 cm |
| C). 16 cm |
| D). 15 cm |
|
90). If the height of the right circular cone is increased by 200% and the radius of the base is reduced by 50%, then the volume of the cone
| A). increases by 25% |
| B). increases by 50% |
| C). remains unchanged |
| D). decreases by 25% |
|
