Question

Q. Let volume of 2nd sphere V2=x
Let the volume of 1st sphere be V1=4x
Radius of 2nd sphere = r2 = L2=3 cm
Radius of larger sphere=r1=L1=?

Answer 1

Volume of a sphere of radius 'r' =

3

4

πr

3

Let r

1

be the radius of the first sphere and r

2

and be the radius of the second sphere.

Given, ratio of their volumes is: V

1

:V

2

=1:8

3

4

πr

1

3

:

3

4

πr

3

2

h=1:8

r

1

3

:r

2

3

=1:8

=>r

1

:r

2

=1:2

Surface area of a sphere of radius 'r' =4πr

2

Now, ratio of their surface areas is:

S

1

:S

2

=4πr

1

2

:4πr

2

2

h

=r

1

2

:r

2

2

=1

2

:2

2

=1:4