(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:
Understanding Total Internal Reflection Conditions
Total Internal Reflection (TIR) is a phenomenon where a wave, like light, travels from a denser medium to a rarer medium and is completely reflected back into the denser medium. This occurs under specific conditions related to the angle of incidence and the properties of the media involved.
Analyzing Statements on Total Internal Reflection
Let's examine each statement to determine its correctness regarding Total Internal Reflection:
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Statement (A): Total internal reflection occurs when a ray of light travels from a rarer transparent medium to a denser medium.
- Analysis: This statement is incorrect. Total internal reflection happens only when light travels from a medium with a higher refractive index (denser medium) to a medium with a lower refractive index (rarer medium). For example, from water to air.
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Statement (B): In total internal reflection, the incident ray of light remains in the same medium after reflection.
- Analysis: This statement is correct. The defining characteristic of TIR is that the light does not pass into the second (rarer) medium; instead, it is entirely reflected back into the first (denser) medium. This behavior is similar to reflection from a mirror.
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Statement (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.
- Analysis: This statement is correct. Total internal reflection is a form of reflection. Therefore, it must obey the fundamental law of reflection, which states that the angle of incidence ($\theta_i$) is always equal to the angle of reflection ($\theta_r$). Both angles are measured with respect to the normal to the surface. So, $\theta_i = \theta_r$.
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Statement (D): In total internal reflection inside a denser medium there is no angle of refraction.
- Analysis: This statement is correct. When total internal reflection occurs, it means that refraction does not happen. The angle of incidence exceeds the critical angle ($\theta_c$), preventing the light ray from entering the rarer medium. If light were refracted, there would be an angle of refraction. Since TIR means all light is reflected, there is no refracted ray and thus no angle of refraction.
Conclusion on Correct Statements
Based on the analysis, statements (B), (C), and (D) accurately describe aspects of Total Internal Reflection.
Identifying the Correct Option
The option that includes only the correct statements (B), (C), and (D) is the correct answer.
Important Questions from Ray Optics and Optical Instruments
The graph correctly representing the variation of image distance v for a convex lens of focal length f versus object distance u is:
Two slits are made 0.1 mm apart, and the screen is placed 2 m away. The fringe separation when a light of wavelength 500 nm is used is:
Resolving power of a telescope can be increased by increasing:
Match List - I with List - II.
List - I List - II (A) Contracting of Eye ball (I) Myopia (B) Controls the shape of eye lens (II) Cornea (C) Elongation of eye ball (III) Ciliary Muscle (D) Control the light entering in eyes (IV) Hypermetropia Choose the correct answer from the options given below:
Four lenses of focal length ±5cm and ±200cm are available for making a telescope. To produce the largest magnification, the focal length of the eyepiece should be:
