#### Answers

The principle that if a beam of light is reflected back on itself, it will traverse the same path or paths as it did before reversal.

**The principle of reversibility states that light will follow exactly the same path if its direction of travel is reversed.**

Hence:

Using Snell 's Law,

r | = | i | = |

| 1 _{2} n _{1} |

It follows that

| 1 _{2} n _{1} |

Sorry ,

Using Snell 's Law,

r | = | i | = |

| 1 _{2} n _{1} |

It follows that

| 1 _{2} n _{1} |

this is the final equation.Sorry again

how

when light strikes any reflecting surface, then it goes in the same medium . if mirror is placed at right angle to the reflected ray then it returns in the same path from where it incident without any deviation

show that incident ray of light is parallel to the emergent ray of light when light falls obliquely on a side of a rectangular glass slab

i don 't know

we can prove this by a expiriment using a glass salb

since the opposite faces or refracting surfaces are parallel incident ray and emergent ray are ll

The answer is : We know that "ANGLE i = ANGLE e" & "ANGLE R1 = ANGLE R2". As External & internal Angles r equal. The lines are Parallel

when light strikes any reflecting surface, then it goes in the same medium . if mirror is placed at right angle to the reflected ray then it returns in the same path from where it incident without any deviation

Please refer to the following link -

http:// www. meritnation. com/ ask - answer / question / plzz - explain - principle - of - reversibility - of - light/ ray -optics - and - optical - instruments / 1680674

Please refer to the following link -

http:// www. meritnation. com/ ask - answer / question / plzz - explain - principle - of - reversibility - of - light/ ray -optics - and - optical - instruments / 1680674

Please refer to the following link -

http:// www. meritnation. com/ ask - answer / question / plzz - explain - principle - of - reversibility - of - light/ ray -optics - and - optical - instruments / 1680674

Please refer to the following link -

Please refer to the following link -

Please refer to the following link -