Question map
A ray of light travels from a medium of refractive index to a medium of refractive index n 2. If angle of incidence is i and angle of refraction sin i . is r, then is equal to
Explanation
The correct answer is Option 3. This question is based on Snell’s Law of Refraction, which governs how light behaves when passing from one transparent medium to another.
According to Snell’s Law, the ratio of the sine of the angle of incidence (i) to the sine of the angle of refraction (r) is constant and is equal to the refractive index of the second medium (n2) relative to the first medium (n1). Mathematically, this is expressed as:
n1 sin i = n2 sin r
To find the value of sin i / sin r, we rearrange the formula:
- sin i / sin r = n2 / n1
Therefore, Option 3 is correct as it represents the relative refractive index (n21). Other options are incorrect because they likely represent the inverse ratio (n1/n2) or unrelated mathematical products that violate the fundamental law of refraction.