(a) Explain with reason, how the power of a diverging lens changes when (i) it is kept in a medium of refractive index greater than that of the lens, (ii) incident red light is replaced by violet light.
(b) Three lenses `L_(1), L_(2), L_(3)` each of focal length 30 cm are placed co-axially as shown in the figure. An object is held at 60 cm from the optic center of lens `L_(1)`. The final real image is formal at the focus of `L_(3)`. Calculate the separation between (i) `(L_(1) and L_(2)) and " (ii) " (L_(2) and L_(3))`.

Explanation

### Solution:

**Part (a):**

1. **Power of a Diverging Lens in Different Media:**
- The power (P) of a lens is given by the formula:
\[
P = \frac{1}{f}
...