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A lens (mu=1.5) is coated with a thin fi...

A lens (`mu=1.5`) is coated with a thin film of refractive index `1.2` order to reduce the reflected form its surface at`lambda=4800Å`.Find the maximum thickness of the film which will minimized the intensity of the reflected light .(Assume near normal incidence)

Text Solution

Verified by Experts

The correct Answer is:
`10^(-7)m`
Path difference =`(lambda)/(2)`
`2mu_(1)t=(lambda)/(2)`
`t=(lambda)/(4mu_(1))rArr t=4800Å/(4xx1.2)`
`t=1000Å implies t=10^(-7)m`
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