The ratio of thickness of plates of to transparent medium a and b is 6...
The ratio of thickness of plates of to transparent medium a and b is 6...
**Introduction:**
In this problem, we are given the ratio of the thickness of two transparent plates, A and B, and we need to find the refractive index of B with respect to A. We are also given that light takes an equal amount of time to pass through both plates. To solve this problem, we will use the concept of optical path length and the formula for the refractive index.
**Understanding the Problem:**
1. We have two transparent plates, A and B.
2. The thickness of plate A is represented as '6x', and the thickness of plate B is represented as '4x'.
3. The time taken by light to pass through both plates is the same.
**Solution:**
1. Let's assume the speed of light in a vacuum is 'c'.
2. The refractive index of a medium is defined as the ratio of the speed of light in a vacuum to the speed of light in that medium.
3. The refractive index (n) can be calculated using the formula: n = c/v, where 'v' is the speed of light in the medium.
4. As the time taken by light to pass through both plates is the same, we can say that the optical path length is the same for both plates.
5. The optical path length is given by the product of the refractive index and the thickness of the medium. So, the optical path length for plate A is 'nA * 6x', and for plate B, it is 'nB * 4x'.
6. Since the optical path length is the same for both plates, we can write the equation: nA * 6x = nB * 4x.
7. Simplifying the equation, we get: nB/nA = 6/4 = 3/2.
8. Therefore, the refractive index of B with respect to A is 3/2.
**Conclusion:**
The refractive index of B with respect to A is 3/2. This means that the speed of light in medium B is one and a half times the speed of light in medium A.