Home
Class 12
PHYSICS
In figure, the reflected ray B makes an ...

In figure, the reflected ray B makes an angle `90^@` with the ray C. If I,`r_1 and r_2` are the angles of incidence, reflection and refraction, respectively. Then, the critical angle of the medium is

A

`sin^-1(tan i)`

B

`sin^-1(cot i)`

C

`r_1`

D

`r_2`

Text Solution

Verified by Experts

The correct Answer is:
A
`r_1=i and r_2=90^@-r_1=90^@-i`
Now, `mu_Rsini_R=mu_Dsini_D`
or `mu_R/mu_D=sin theta_C=(sini_D)/(sini_R)=sini/(sin(90^@-1))`
or `sin theta_C=sini/cosi=tani`
`rArr theta_C=sin^-1(tani)`
Promotional Banner

Topper's Solved these Questions

  • REFRACTION OF LIGHT

    DC PANDEY|Exercise Objective Questions|1 Videos

  • REFRACTION OF LIGHT

    DC PANDEY|Exercise Level 1 Subjective|29 Videos

  • REFRACTION OF LIGHT

    DC PANDEY|Exercise Level 1 Assertion And Reason|13 Videos

  • REFLECTION OF LIGHT

    DC PANDEY|Exercise Subjective|9 Videos

  • SEMICONDUCTORS

    DC PANDEY|Exercise Subjective|12 Videos

Similar Questions

Explore conceptually related problems

A ray of light passes from a denser medium to a rarer medium at an angle of incidence i. The reflected and refracted rays make an angle of 90^@ with each other. The angle of reflection and refraction are resepectively r and r'. The critical angle is given by :

A ray of light from a denser medium strikes a rarer medium at angle of incidence i . The refrected and the refracted rays make an angle of 90^@ with each other. The angles of reflection and refraction are r and r^' respectively. The critical angle is (i) sin^-1(tanr) (ii) sin^-1(tani) (iii) sin^-1(tanr) (iv) tan^-1(tani)

A ray of light from a denser medium strikes a rarer medium at an angle of incidence I (see figure ). The reflected and refracted rays make an angle of 90^(@) with each other. The angles of reflection and refraction are r and r^() . The critical angle is

A ray of light from a denser medium strikes a rarer medium at an angle of incidenc i. The reflected and refracted rays make an angle of pi//2 with each other. If the angles of reflection and refraction are r and r^(') , then the criticall angle will be

For which angle of incidence reflected ray is completely polarised?

A ray of light from a denser medium strike a rarer medium at an angle of incidence I (see Fig). The reflected and refracted rays make as angle of 90degrees with each other. The angles of reflection and refraction are r and r The critical angle is

At polarising angle, the angle between reflected and refracted rays is

A ray of light is incident at an angle i from denser to rare medium. The reflected and the refracted rays are mutually perpendicular. The angle of reflection and the angle of refraction are respectively r and r'. Then the critical angle will be:

If a light ray incident on a plane mirror makes an angle 30^(@) with it, find the angle of incidence and angle of reflection.

DC PANDEY-REFRACTION OF LIGHT-Level 1 Objective
  1. When light enters from air to water, then its

    Text Solution

    |

  2. In the figure shown sin i/sin r is equal to

    Text Solution

    |

  3. In figure, the reflected ray B makes an angle 90^@ with the ray C. If ...

    Text Solution

    |

  4. A prism of apex angle A=60^@ has the refractive index mu=sqrt2. The an...

    Text Solution

    |

  5. A thin equi-convex lens is made of glass of refractive index 1.5 and i...

    Text Solution

    |

  6. A ray of light, travelling in a medium of refractive index mu, is inci...

    Text Solution

    |

  7. The given equi-convex lens is broken into four parts and rearranged as...

    Text Solution

    |

  8. A thin convergent glass lens (mug=1.5) has a power of +5.0D. When this...

    Text Solution

    |

  9. Two convex lenses of focal length 10 cm and 20 cm respectively placed ...

    Text Solution

    |

  10. A prism can have a maximum refracting angle of (thetaC=critical angle ...

    Text Solution

    |

  11. A ray is ihncident at an angle of incidence ii on one surface of a pri...

    Text Solution

    |

  12. The refracting angle of a prism is A and refractive index of the mater...

    Text Solution

    |

  13. A prism of refractive index sqrt2 has refractive angle 60^@. In the or...

    Text Solution

    |

  14. The focal length of a combination of two lenses is doubled if the sep...

    Text Solution

    |

  15. A convexo-concave convergent lens is made of glass of refractive index...

    Text Solution

    |

  16. An optical system consists of a thin convex lens of focal length 30 cm...

    Text Solution

    |

  17. In the figure shown, the angle made by the light ray with the normal i...

    Text Solution

    |

  18. For refraction through a small angled prism, the angle of minimum devi...

    Text Solution

    |

  19. A ray of light passes from vaccum into a medium of refractive index n....

    Text Solution

    |

  20. A thin convex lens of focal length 30 cm is placed in front of a plane...

    Text Solution

    |