What is the least radius through which a...

What is the least radius through which an optical fiber of core diameter 0.05 mm may be bent (as shown in figure) without serious loss of light? The refractive index of the core is 1.6 and that of cladding is 1.5.

0.28 mm

0.58 mm

0.8mm

1 mm

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The correct Answer is:

`theta_("incident") gt theta_("optical")`
`r gt .75` mm

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