Question

Assume that there is no compression of roving during winding and each coil of a layer is placed directly over the coil of the previous layer. A full roving bobbin consisting of 50 layers of roving is wound on an empty bobbin of 60 mm diameter. If the diameter of the roving is 1 mm, then the diameter (mm) of the full bobbin (in integer) is ________________.

Hint:

The final diameter of the bobbin can be calculated by adding twice the total thickness of the layers to the initial diameter of the bobbin.

Answer 1

Correct Answer: 160

The diameter of the full bobbin can be calculated using the formula for the total diameter of the wound bobbin: \[ D_{\text{total}} = D_{\text{initial}} + 2 \times (\text{number of layers}) \times (\text{diameter of roving}). \] Substituting the given values: \[ D_{\text{total}} = 60 + 2 \times 50 \times 1 = 160 \, \text{mm}. \] Final Answer: \[ \boxed{160}. \]