What will be the change in focal length of a concave mirror when it is placed in water ?

Explanation

To determine the change in focal length of a concave mirror when it is placed in water, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Formula for Focal Length**:
The focal length (F) of a mirror is given by the formula:
\[
F = \frac{R}{2}
...