Time taken by light to pass through a glass slab

To calculate the time taken by light to pass through a glass slab, we need to consider the thickness of the slab and its refractive index. Let's break down the calculation into several steps:

Step 1: Identify the given values
- Thickness of the glass slab: 4 mm
- Refractive index of the glass slab: 1.5

Step 2: Determine the speed of light in the glass slab
The speed of light in a medium is given by the equation:

v = c / n

where v is the speed of light in the medium, c is the speed of light in a vacuum (approximately 3 x 10^8 m/s), and n is the refractive index of the medium.

Substituting the given values, we can calculate the speed of light in the glass slab:

v = (3 x 10^8 m/s) / 1.5 = 2 x 10^8 m/s

Step 3: Calculate the time taken by light to pass through the glass slab
The time taken by light to pass through the glass slab can be determined using the equation:

t = d / v

where t is the time taken, d is the distance traveled (thickness of the slab), and v is the speed of light in the glass slab.

Substituting the given values:

t = (4 x 10^-3 m) / (2 x 10^8 m/s) = 2 x 10^-11 s

Therefore, the time taken by light to pass through a 4 mm thick glass slab with a refractive index of 1.5 is 2 x 10^-11 seconds.

Summary:
- Thickness of the glass slab: 4 mm
- Refractive index of the glass slab: 1.5
- Speed of light in the glass slab: 2 x 10^8 m/s
- Time taken by light to pass through the glass slab: 2 x 10^-11 seconds

2*10-¹¹ is answer by using formula t=mu d/c