A convex lens of focal length 30 cm is placed coaxially in contact with a concave lens of focal length 40 cm. Determine the power of the combination. Will the system be converging or diverging in nature?

Explanation

To solve the problem of determining the power of a combination of a convex lens and a concave lens, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Focal Lengths**:
- The focal length of the convex lens (f1) is +30 cm (positive because it is a convex lens).
- The focal length of the concave lens (f2) is -40 cm (negative because it is a concave lens).

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