Correct Option: B

According to the question Base of hemisphere = Base of cone
i.e. radius of hemisphere = radius of cone ...(i)
and height of hemisphere = height of cone ...(ii)
We know that height of hemisphere = radius of hemisphere
⇒ height of cone = radius of hemisphere
[From (i)]
⇒ height of cone = radius of cone
[From (ii)]
Now, Curved surface area of hemisphere = 2πr²
Curved surface area of cone = πr√r² + h²
= √r² + h²(r = h)
= √2r² = πr × √2r
= √2πr²
∴ Ratio of curved surface area of hemisphere and cone
= 2πr² : √2πr² = 2 : √2 = √2 : 1