Which of the following statements are correct?
(A) Total internal reflection occurs when a ray of light travels from a rarer transparent medium to a denser medium.
(B) In total internal reflection, the incident ray of light remains in the same medium after reflection.
(C) In total internal reflection, the angle of incidence inside the denser transparent medium is equal to the angle of reflection in the same medium.
(D) In total internal reflection inside a denser medium there is no angle of refraction
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (B), (C) and (D) only
Total internal reflection happens at the boundary of a denser and a rarer medium when the angle of incidence in the denser medium exceeds the critical angle.
(A) Total internal reflection occurs when a ray of light travels from a rarer transparent medium to a denser medium. — Incorrect. It occurs only when the ray travels from the denser medium to the rarer one.
(B) In total internal reflection, the incident ray of light remains in the same medium after reflection. — Correct. The whole light is reflected back into the denser medium.
(C) In total internal reflection, the angle of incidence inside the denser transparent medium is equal to the angle of reflection in the same medium. — Correct. The laws of reflection hold here too.
(D) In total internal reflection inside a denser medium there is no angle of refraction — Correct. No light is refracted into the rarer medium, so there is no refracted ray and no angle of refraction.
NCERT (2026-27):
Total Internal Reflection – “When light travels from an optically denser medium to a rarer medium at the interface, it is partly reflected back into the same medium and partly refracted to the second medium.”
Total Internal Reflection – “… If the angle of incidence is increased still further (e.g., the ray AO4), refraction is not possible, and the incident ray is totally reflected. This is called total internal reflection. … In total internal reflection, on the other hand, no transmission of light takes place.”