To determine the approximate focal length of the given convex lens by focusing a distant object (say, a sign board), you try to focus the image of the object on a screen. The image you obtain on the screen is always:

Options

A. erect and laterally inverted
B. erect and diminished
C. inverted and diminished
D. virtual, inverted and diminished

Explanation

To determine the approximate focal length of a given convex lens by focusing a distant object, follow these steps:

### Step-by-Step Solution:

1. **Set Up the Experiment**: Place the convex lens on a stable surface. Ensure that you have a distant object, such as a signboard, positioned far away from the lens. The object should ideally be at infinity for accurate results.

2. **Position the Screen**: Place a screen on the opposite side of the lens. The screen will be used to capture the image formed by the lens.

3. **Adjust the Lens**: Look through the lens at the distant object and adjust the position of the screen until you see a clear image of the object on the screen.

4. **Observe the Image**: As you focus the image on the screen, you will notice that the image formed is point-sized, inverted, diminished, and real. This is because when the object is at infinity, the rays of light coming from the object are parallel and converge at the focal point of the lens.

5. **Record the Focal Length**: The distance from the lens to the screen, when the image is sharply focused, is approximately equal to the focal length of the lens.

### Conclusion:
The image you obtain on the screen is always point-sized, inverted, diminished, and real when focusing on a distant object with a convex lens.

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