law of refraction and total internal reflection questions with solutions

Showing 1–10 of 81 questions

• MCQeasyGeometrical opticslaw of refraction and total internal reflection

  A monochromatic light of frequency 5×10¹⁴ Hz travelling through air is incident on a medium of refractive index 2. The wavelength of the refracted light is:

  Options

  • Option A

    300 nm

  • Option B

    500 nm

  • Option C

    400 nm

  • Option D

    600 nm

  Check answerShow answer

  JEE Mains 2025 3 April Evening Shift

  Open question & full solution →
• MCQmediumGeometrical opticslaw of refraction and total internal reflection

  A point source is 15 cm below a liquid-air surface. The radius of its escape circle is 20 cm. Find the refractive index of the liquid.

  Options

  • Option A

    5/4

  • Option B

    4/3

  • Option C

    3/2

  • Option D

    5/3

  Check answerShow answer

  JEE MainsNEET

  Open question & full solution →
• Multi-correctmediumGeometrical opticslaw of refraction and total internal reflection

  For colour-selective TIR at a glass-air interface in normal dispersion, select all correct statements.

  Select all that apply

  • Option A

    The incidence μst lie between the critical angles of two colours

  • Option B

    The colour with larger refractive index has smaller critical angle

  • Option C

    A colour with smaller critical angle may be totally reflected while another emerges

  • Option D

    Frequency changes on reflection

  Check answerShow answer

  JEE MainsNEET

  Open question & full solution →
• ParagraphdifficultGeometrical opticslaw of refraction and total internal reflection

  Light guidance in an optical fiber can be understood by considering a structure comprising of thin solid glass cylinder of refractive index n₁ surrounded by a medium of lower refractive index n₂. The light guidance in the structure takes place due to successive total internal reflections at the interface of the media n₁ and n₂ as shown in the figure. All rays with the angle of incidence i less than a particular value of iₘ are confined in the medium of refractive index n₁. The numerical aperture (NA) of the structure is defined as sin iₘ.

  

  Sub-question 1

  For two structures namely S₁ with n₁ = √45/4 and n₂ = 3/2, and S₂ with n₁ = 8/5 and n₂ = 7/5 and taking the refractive index of water to be 4/3 and that of air to be 1, the correct option(s) is (are)

  Select all that apply

  • Option A

    NA of S₁ immersed in water is the same as that of S₂ immersed in liquid of refractive index 16/(3√15).

  • Option B

    NA of S₁ immersed in liquid of refractive index 6/√15 is the same as that of S₂ immersed in water.

  • Option C

    NA of S₁ placed in air is the same as that of S₂ immersed in liquid of refractive index 4/√15.

  • Option D

    NA of S₁ placed in air is the same as that of S₂ placed in water.

  Sub-question 2

  If two structures of same cross-sectional area, but different numerical apertures NA₁ and NA₂ (NA₂ < NA₁) are joined longitudinally, the numerical aperture of the combined structure is

  Options

  • Option A

    NA₁NA₂/(NA₁ + NA₂)

  • Option B

    NA₁ + NA₂

  • Option C

    NA₁

  • Option D

    NA₂

  Check answerShow answer

  JEE Advanced

  Open question & full solution →
• MCQmediumGeometrical opticslaw of refraction and total internal reflection

  For normal dispersion, μV>μR. A white ray inside glass is incident on a glass-air surface while the incidence angle is gradually increased. Which colour starts undergoing TIR first?

  Options

  • Option A

    Red

  • Option B

    Violet

  • Option C

    All colours simultaneously

  • Option D

    Green

  Check answerShow answer

  JEE MainsNEET

  Open question & full solution →
• MCQmediumGeometrical opticslaw of refraction and total internal reflection

  Consider light travelling from a medium A to medium B separated by a plane interface. If the light undergoes total internal reflection during its travel from medium A to B and the speed of light in media A and B are 2.4 × 10⁸ m/s and 2.7 × 10⁸ m/s respectively, then the value of critical angle is :

  Options

  • Option A

    cot⁻¹(3/√13)

  • Option B

    sin⁻¹(9/8)

  • Option C

    tan⁻¹(8/√17)

  • Option D

    cos⁻¹(8/9)

  Check answerShow answer

  JEE Mains 202623 January Morning Shift

  Open question & full solution →
• MCQmediumGeometrical opticslaw of refraction and total internal reflection

  The critical angle of a material with air is 30°. What is its refractive index?

  Options

  • Option A

    √2

  • Option B

    √3

  • Option C

    2

  • Option D

    2/√3

  Check answerShow answer

  JEE MainsNEET

  Open question & full solution →
• Multi-correctmediumGeometrical opticslaw of refraction and total internal reflection

  For normal dispersion in glass, select all correct statements.

  Select all that apply

  • Option A

    μV>μR

  • Option B

    CV<CR

  • Option C

    Violet can undergo TIR while red emerges for a suitable incidence angle

  • Option D

    Red always undergoes TIR before violet

  Check answerShow answer

  JEE MainsNEET

  Open question & full solution →
• MCQeasyGeometrical opticslaw of refraction and total internal reflection

  Assertion (A): The refractive index of glass is greater than that of air. Reason (R): Optical density is directly proportional to mass density, which causes a proportional refractive index. Choose the correct answer.

  Options

  • Option A

    A is false but R is true

  • Option B

    Both A and R are true and R explains A

  • Option C

    A is true but R is false

  • Option D

    Both A and R are true but R does not explain A

  Check answerShow answer

  JEE Mains 2025 7 April Evening Shift

  Open question & full solution →
• Multi-correctmediumGeometrical opticslaw of refraction and total internal reflection

  A ray of light from a denser medium strikes a rarer medium at an angle of incidence i. The reflected and refracted rays make an angle of 90° with each other. The angles of reflection and refraction are i and r. The critical angle is :-

  

  Select all that apply

  • Option A

    sin⁻¹ (tan r)

  • Option B

    sin⁻¹ (tan i)

  • Option C

    sin⁻¹ (tan r')

  • Option D

    tan⁻¹ (sin i)

  Check answerShow answer

  JEE MainsJEE Advanced

  Open question & full solution →