Calculate the radius of the curvature an equi-concave lens refrective index 1.5, when it is kept in a medium refrecation index 1.4, to have a power of -5D ?

Explanation

To solve the problem of calculating the radius of curvature of an equi-concave lens with a refractive index of 1.5 when placed in a medium with a refractive index of 1.4, and to achieve a power of -5 diopters, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Given Values:**
- Refractive index of the lens, \( \mu_2 = 1.5 \)
- Refractive index of the medium, \( \mu_1 = 1.4 \)
- Power of the lens, \( P = -5 \) D
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