A converging lens has a focal length of `20 cm` in air. It is made of a material of refractive index `1.6`. If it is immersed in a liquid of refractive index `1.3`, what will be its new foacl length ?

Explanation

To find the new focal length of a converging lens when it is immersed in a liquid, we can use the Lensmaker's formula. Here’s a step-by-step solution:

### Step 1: Identify the given values
- Focal length in air, \( f_a = 20 \, \text{cm} \)
- Refractive index of the lens material, \( \mu = 1.6 \)
- Refractive index of the liquid, \( \mu_l = 1.3 \)

### Step 2: Write the Lensmaker's formula for the lens in air
...