Question

A copper rod of diameter 2cm and length 10cm is drawn into a wire of uniform thickness and length 10cm . Find the thickness of the wire

Answer 1

Diameter of rod = 2cm

Radius of rod = 1cm

Pir^2h

= Pi×1×1×10

=10pi

Radius of wire = ?

H = 10m = 1000cm

Pir^2h

= Pi×r×r×1000

1000pir^2

10pi =1000r^2×pi

1÷100 = r^2

R = 1÷10

Answer 2

Answer:

0.067cm

Step-by-step explanation:

Given diameter of the copper rod = 1 cm

So, radius(r) of the copper rod = 1/2 cm

Let R is the radius of the cross section(circular) of the wire.

Now, according to the question,

     πR² *(18*100) = π(1/2)2 *8

=> R² *(18*100) = (1/2)2 *8

=> R² *(18*100) = 8/4

=> R²*(18*100) = 2

=> R²= 2/(18*100)

=> R² = 1/(9*100)

=> R = √{1/(9*100)}

=> R = 1/(3*10)

=> R = 1/30

Now, thickness of the wire = 2r = 2 * 1/30 = 2/30 = 1/15 = 0.067 cm