Q.

12 spheres of the same size are made from melting a solid cylinder of 16 cm diameter and 2 cm height. The diameter of each sphere is:

1 3 cm      
2 2 cm  
3 3 cm  
4 4 cm  

Ans.

(4)

Radius of cylinder=162=8 cm

Let  r cm be the radius of each sphere.

hen one solid shape is converted into another, the volume remains the same

 Volume of the solid cylinder =12× volume of one sphere

π×(8)2×2=12×43πr3

128=16r3r3=8r=2 cm

Diameter of sphere =2r=2×2=4 cm

 Option (d) is correct.