Question

A metallic slab having dimensions 35 cm × 11 cm × 20 cm is melted and recasted in the shape of a wire of radius 0.7 mm. What is the length of the wire (in m)? (Use π = \(\dfrac{22}{7}\))
1. 1590 m
2. 110 m
3. 500 m
4. 5000 m

Answer 1

Correct Answer - Option 4 : 5000 m

Given:

Dimensions of metallic slab = 35 × 11 × 20

Radius of wire = 0.7mm

Formula:

Volume of cuboid = l × b × h

Volume of cylinder = πr²h

Calculation:

Volume of metallic slab = 35 × 11 × 20 = 7700 cubic.cm

Volume of cylindrical wire = 7700 cubic.cm

Radius of wire = 0.7mm = 0.07cm

But,

Volume of cylindrical wire = π × 0.7² × h

⇒ 7700 = 22/7 × 0.07 × 0.07 × h

⇒ h = 500000 cm

⇒ h = 5000 m

∴ Length of wire is 5000 m.