SSC CGL Tier II 12 Jan 2017 Paper 1

Question : 54 of 100

Marks: +1, -0

The radius of a sphere is 6 cm. It is melted and drawn into a wire of radius 0.2 cm. The length of the wire is

Solution:

(4) In both cases, volume will remain same.
Volume of sphere =

{ 4 } /{ 3 } \π r ^ { 3 }

= { 4 } /{ 3 } \π (6) ^ { 3 }

= 288\π

cu. cm.
If the length of wire be h cm.,
then

⇒ \π { R } ^ { 2 } h = 288 \π

⇒ ( 0.2 ) ^ { 2 } × h = 288

⇒ h = { 288 }/ { 0.04 } = 7200 { \cm }

= 72

metre

Go to Question:

Prev Question

Next Question