Question

Torme
12. A copper rod of diameter 2 cm and length 10 cm
is drawn into a wire of uniform thickness and
length 10 m. Find the thickness of the wire.
(CBSE 2012)​

Answer 1

Answer:

Rod and wire, both having the section of the cylinder.

Here volume change takes place,

So,

Volume of rod = volume of wire.

For rod,

D = 2 cm, R = D/2 = 1 cm

L = 10 cm

For drawn wire,

d = ?, r = d/2

l = 10m = 1000 cm.

Volume of rod = volume of wire

πR2L = πr2l

R2L = r2l

1 × 10 = r2 × 1000

1/100 = r2

1/10 = r

r = 0.1 cm = 1 mm.

d = 2r = 2 mm.

Step-by-step explanation:

Hope it helps you