Question

A wire of 4mm diameter is made by pulling a metallic cube whose side is 1 cm the length of the wire is

Answer 1

The length of the wire is 7.95 cm.

Step-by-step explanation:

1. Side of metallic cube(a) = 1 cm

  Diameter of wire (D) = 4 mm = 0.4 cm

  So

  Radius of wire (R) = 0.2 cm

  Length of wire (L) =unknown

2. Volume of cube (V) =$side^{3}$ =$a^{3}$

 

  $\mathbf{\textrm{Volume of cube (V)} =1^{3}= 1 \ cm^{3}}$

3. $\mathbf{\textrm{Volume of wire (V)} =\pi\times R^{2}\times L }$

4. Here

   Volume of material of wire = Volume of material cube

   $\mathbf{\pi\times R^{2}\times L =1}$

   $\mathbf{\frac{22}{7}\times 0.2^{2}\times L =1}$

  So

 Length of wire (L) =7.95 cm