Answer: B

Here, we have to find total length of semi-circles l₁ , l ₂, l₃, .............l₁₃ with centre A and B alternatively.
Here, r₁ = 0.5cm, r₂= 1 cm, r₃ = 1.5 cm and so on
Circumference = πr
Total length of spiral = πr₁+πr₂+πr₃+......+πr₁₃
=> π(0.5+1+1.5+2+..........) = π*0.5 [1+2+3+4.....+13]
=> 22/7 * 0.5 * 13*14/2 = 11*13 = 143 cm.

Answer: D
As all of them have same base so they have same radius.
Suppose their radius is r and height is h.
Curved surface area of cylinder = 2πrh = 2πr²
Curved surface area of hemisphere = 2πr²
Curved surface area of cone = πr(r² +h² )^1/2  = πr²√2
Ratio between them = 2πr² : 2πr² : πr²√2
= √2 : √2 : 1