A Lens with a Refractive Index of 1 $\lambda$ Denotes the Wavelength of the Incident Light in Air, What

question 40

Multiple Choice

A lens with a refractive index of 1.5 is coated with a material of refractive index 1.2 in order to minimize reflection.If $\lambda$ denotes the wavelength of the incident light in air, what is the thinnest possible such coating?

• A)0.5\(\lambda\)
• B)0.417\(\lambda\)
• C)0.3\(\lambda\)
• D)0.25\(\lambda\)
• E)0.208\(\lambda\)

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Definitions:

Hysteresis

A phenomenon where the response of a system to changes in input is dependent on its current state or previous inputs, often to prevent rapid oscillation.

Through-beam Sensor

A type of photoelectric sensor where the emitter and receiver are positioned opposite each other, detecting objects when the beam is interrupted.

Sensing Range

The distance within which a sensor can detect the presence of an object or a signal.