Question : The radius of the base of a solid right circular cone is 8 cm and its height is 15 cm. The total surface area of the cone is:
Option 1: 200$\pi$
Option 2: 120$\pi$
Option 3: 136$\pi$
Option 4: 128$\pi$
Correct Answer: 200$\pi$
Solution : Given: Radius, $r\ = 8$ cm Height, $h\ =\ 15$ cm Let $l$ be the slant height. As we know, $l^2\ =\ r^2\ +\ h^2$ $\Rightarrow l^2\ =\ 8^2\ +\ 15^2$ $\Rightarrow l^2\ =\ 64\ +\ 225$ $\Rightarrow l^2\ =\ 289$ $\therefore l\ =\ 17$ cm Now, Total Surface Area of the cone $=\pi r(r\ +\ l)\ =\ \pi\ \times 8 \times (8+ 17)\ =\ 200\pi$ Hence, the correct answer is $200\pi$.
Result | Eligibility | Application | Selection Process | Cutoff | Admit Card | Preparation Tips
Question : The volume of a solid right circular cone is $600 \pi \;\text{cm}^3$ and the diameter of its base is 30 cm. The total surface area (in cm2) of the cone is:
Question : The curved surface area of a right circular cone is $156 \pi$ and the radius of its base is 12 cm. What is the volume of the cone, in cm3?
Question : The total surface area of a solid metallic hemisphere is 462 cm2. This is melted and moulded into a right circular cone. If the radius of the base of the cone is the same as that of the hemisphere, then its height is: (use $\pi=\frac{22}{7}$)
Question : The height and curved surface area of a right circular cylinder are $7~\text{cm}$ and $70\pi~\text{cm}^2$. Its total surface area is:
Question : The radius of the ends of a frustum of a solid right-circular cone 45 cm high is 28 cm and 7 cm. If this frustum is melted and reconstructed into a solid right circular cylinder whose radius of base and height are in the ratio 3: 5, find the curved surface area (in
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile