A magician during a show makes a glass lens `mu = 1.5` disappear in a through of liquid. What is the refractive index of the liquid ? Is the liquid water ?

Explanation

To solve the problem of finding the refractive index of the liquid in which the glass lens disappears, we can follow these steps:

### Step 1: Understand the concept of disappearance
When the glass lens disappears in the liquid, it means that the refractive index of the liquid is equal to the refractive index of the glass lens. This is because when two materials have the same refractive index, light travels through them without bending, making the boundary between them invisible.

### Step 2: Identify the refractive index of the glass lens
The problem states that the refractive index (μ) of the glass lens is 1.5.

...