SSC GD 2023 PYQ — Question 52

The correct answer is option 2 i.e. 550 cm²

Given:

Area of base of cone = 154 cm² 

Height of cone = 24 cm

Concept Used:

Area of base of cone = $\pi r^2$

Curved suface area of cone = $\pi rl$

Slant height, l² = r² + h² 

Explanation:

According to the guven question,

$\pi r^2$ = 154

⇒ ${22 \over 7} \times r^2 = 154$

⇒ r = 7 cm

Now, Slant height, l² = r² + h² 

⇒ l² = 49 + 576

⇒ l² = 625

⇒ l = 25 cm

Now, CSA of cone = $\pi rl$ 

⇒ ${22 \over 7} \times 7 \times 25$ = 550 cm² 

Hence the required answer is 550 cm² .