Question

The curved surface area of a sphere is given as $1256c{m^2}$ .Find the radius of the sphere and choose the correct option from the below given choices (use $\pi = 3.14$ )
A. 100 cm
B. 10 cm
C. 1 cm
D. 314 cm

Answer 1

Hint- Make use of the formula of curved surface area of a sphere i.e CSA=$4\pi {r^2}$ and solve it

Complete step-by-step answer:
Given that the curved surface area of a sphere=$1256c{m^2}$
We have to find out the radius of the sphere
So, for this let’s make use of the formula of curved surface area of a sphere and solve it
The curved surface area of a sphere is given by the formula
CSA=$4\pi {r^2}$
So, let us substitute the values in the formula , so we get
1256=4$ \times 3.14 \times {r^2}$
$
   \Rightarrow {r^2} = \dfrac{{1256}}{{4 \times 3.14}} \\
   \Rightarrow {r^2} = 100 \\
$
So, from this we get r=10cm
So, the radius=10cm
So, the correct option for this question is option B

Note: In this question, we have been given the curved surface area of the sphere , in case we were given some other quantity like volume of the sphere, then make use of the respective formula and solve the question.