Home
Class 12
PHYSICS
Two plane mirrors A and B are aligned pa...

Two plane mirrors A and B are aligned parallel to each other, as shown in the figure. A light ray is incident at an angle '30degree' at a point just inside one end of A. The plane of incidence coincides with the plane of the figure. The maximum number of times the ray undergoes reflections (including the first one) before it emerges out is

A

(a)28

B

(b)30

C

(c)32

D

(d)34

Text Solution

Verified by Experts

The correct Answer is:
B

`d = 0.2 "tan" 30^(@) = (0.2)/(sqrt(3))`
`(l)/(d) = (2sqrt(3))/(0.2 // sqrt(3)) = 30`

Therefore , maximum number of reflection are 30.
Promotional Banner

Topper's Solved these Questions

ALLEN -GEOMETRICAL OPTICS-EXERCISE-05 (B)
  1. An observer can see through a pin-hole the top end of a thin rod of he...

    Text Solution

    |

  2. Which one of the following spherical lenses does not exhibit dispersio...

    Text Solution

    |

  3. Two plane mirrors A and B are aligned parallel to each other, as shown...

    Text Solution

    |

  4. The size of the image of an object, which is at infinity, as formed by...

    Text Solution

    |

  5. A ray of light is incident at the glass-water interface at an angle I,...

    Text Solution

    |

  6. White light is incident on the interface of glass and air as shown in ...

    Text Solution

    |

  7. An equilateral prism is placed on a horizontal surface. A ray PQ is in...

    Text Solution

    |

  8. A point object is placed at the centre of a glass sphere of radius 6cm...

    Text Solution

    |

  9. A container is filled with water (mu=1.33) upto a height of 33.25 cm. ...

    Text Solution

    |

  10. A convex lens if in contact with concave lens. The magnitude of the ra...

    Text Solution

    |

  11. A point object is placed at distance of 20 cm from a thin plane - con...

    Text Solution

    |

  12. A biconvex lens of focal length f forms a circular image of radius r o...

    Text Solution

    |

  13. A ray of light travelling in water is incident on its surface open to ...

    Text Solution

    |

  14. In an experiment to determine the focal length (f) of a concave mirror...

    Text Solution

    |

  15. Two beams of red and violet colours are made to pass separately throug...

    Text Solution

    |

  16. A light beam is traveling from Region I to region IV (refer figure). T...

    Text Solution

    |

  17. A ball is dropped from a height of 20 m above the surface of water in ...

    Text Solution

    |

  18. A biconvex lens of focal length 15 cm is in front of a plane mirror. T...

    Text Solution

    |

  19. A ray of light travelling in the direction (1)/(2)(hati+sqrt3hatj) is ...

    Text Solution

    |

  20. The image of an object, formed by a plano-convex lens at a distance of...

    Text Solution

    |