Question

what is total internal refraction? And wht is critical angle.

Answer 1

open your text book and read

Answer 2

CRITICAL ANGLE -WHEN A RAY OF LIGHT PASSES FROM A MEDIUM OF HIGHER OPTICAL DENSITY TO A MEDIUM OF LOWER OPTICAL DENSITY ,THE ANGLE OF INCIDENCE AT WHICH THE ANGLE OF REFRACTION BECOMES 90° IS THE CRITICAL ANGLE.

TOTAL INTERNAL REFLECTION-WHEN A RAY OF LIGHT PASSES FROM A MEDIUM OF HIGHER OPTICAL DENSITY TO A MEDIUM OF LOWER OPTICAL DENSITY AT AN ANGLE OF INCIDENCE GREATER THAN THE CRITICAL ANGLE,THE RAY IS REFLECTED BACK TO THE SAME MEDIUM WITH OUT UNDERGOING REFRACTION.THIS KNOWN AS TOTAL INTERNAL REFLECTION.

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