What is the formula to calculate the speed of light in the material ?V= c/n V = n/c V= n × c

To calculate the speed of light in a material, you can use the following formula:

Formula

$V = \frac{c}{n}$

where:

• $V$ is the speed of light in the material,
• $c$ is the speed of light in a vacuum (approximately $3 \times 10^8 \, \text{m/s}$),
• $n$ is the refractive index of the material.

Analysis

1. Understanding the Refractive Index: The refractive index $n$ is a dimensionless number that indicates how much the speed of light is reduced in a medium compared to its speed in a vacuum.
2. Speed of Light in Material: By rearranging this formula, we find that the speed of light decreases as the refractive index increases.

Conclusion

Thus, among the provided options, the correct formula to calculate the speed of light in a material is:

$V = \frac{c}{n}$