A cylinder of base radius 4cm is open at one end . If the ratio of the area of its base to that of its curved surface is 1:4, calculate the height of the cylinder
-
A.
1cm -
B.
2cm -
C.
4cm -
D.
8cm -
E.
16cm
Correct Answer: Option D
Explanation
r= 4cm; base area = (pi)r2; Curve S.A = 2(pi)rh
(frac{base area}{curved area}) = 1/4; (pi)/2(pi)rh
=h = (frac{4 x 4cm}{2})
h= 8cm