Question

a copper wire of diameter 6mm is evenly wrapped on the cylinder of the lenth 18 cm and diameter 49 cm to cover its whole surface . find the lenth of the wire

Answer 1

The lenght of the cylinder is 18cm then No. of turns=18/radius of wire=60 turns Length of wire=No. of turns×lenght of 1 turn where lenght of 1 turn = circumference of cylinder Circumference=154 Length of wire = 154×60=9240

Answer 2

Answer:

4620 cm

Step-by-step explanation:

Given :A copper wire of diameter 6 mm is evenly wrapped on the cylinder of the length 18 cm and diameter 49 cm to cover its whole surface .

To Find : find the length of the wire

Solution:

Diameter of wire = 6 mm = 0.6 cm

Radius of wire =$\frac{Diameter}{2}=\frac{0.6}{2}=0.3 cm$

Height of cylinder = 18 cm

Diameter of cylinder = 49 cm

Radius of cylinder = $\frac{Diameter}{2}=\frac{49}{2}$

No. of rotations of wire on cylinder =$\frac{\text{Height of cylinder}}{\text{Diameter of wire}}$

                                                         $= \frac{18}{0.6}$

                                                         = 30

Circumference of cylinder =$2 \pi r= 2 \times \frac{22}{7} \times \frac{49}{2}$

                                            =154 cm

So, length of wire = $154 \times 30=4620 cm$

Hence the length of the wire is 4620 cm