InterviewSolution
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InterviewSolution
| 1. |
Explain the phenomenon of total internal reflection. |
Answer» Solution :Consider a point object in the denser medium. There will be cone of rays striking the interface. For a ray of light OA, it SUFFERS NORMAL refraction. For any ANGLE of incidence less than critical angle such as ray OB, the refracted ray bends away from teh normal. However for a particular angle of incidence called critical angle, the refracted ray of light grazes the interface. Therefore critical angle for the given pair of media and given wavelength of light may be defined as the angle of incidencein the denser mediumfor which the refractedray is at right angles to the normal drawn at the point of incidence. Fora ray of light such as OD, whose angle of incidence is greater than the criticalangle, there will be no refractionof light, instead the lightbounces BACK intothe same densermedium. This phenomenonof light is knownas the totalinternal reflection. Conditions for the TOTAL internalreflection. (a) Object shouldbe in the densermedium and viewed through rarer medium. (b) Angle of incidence in the denser medium should be more than the critical angle for the given pair of mediaand wavelengthof light. |
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