The image produced by a convex lens depends upon . a. the distance the object is from the lens c. the size of the lens b. the size of the object d. the optical axis The image produced by a convex lens depends upon . a. the distance the object is from the lens c. the size of the lens b. the size of the object d. the optical axis
The Correct Answer and Explanation is:
Correct Answer:
a. the distance the object is from the lens
Explanation
A convex lens, also known as a converging lens, bends light rays inward toward a focal point. The nature of the image produced by a convex lens—whether it is real or virtual, upright or inverted, magnified or diminished—depends primarily on the distance between the object and the lens.
This relationship is governed by the lens formula: 1f=1v−1u\frac{1}{f} = \frac{1}{v} – \frac{1}{u}
Where:
- f is the focal length of the lens (positive for convex lenses),
- v is the image distance from the lens,
- u is the object distance from the lens.
Here’s how image formation varies with object distance:
- Beyond 2F (twice the focal length): The image is real, inverted, and smaller than the object.
- At 2F: The image is real, inverted, and same size as the object.
- Between F and 2F: The image is real, inverted, and magnified.
- At F (focal point): No image is formed, as rays are parallel after refraction.
- Closer than F: The image is virtual, upright, and magnified (like in a magnifying glass).
In contrast:
- Option b (size of the object) only affects how large the actual object is, not the nature of the image.
- Option c (size of the lens) may affect image brightness and clarity, but not the image’s fundamental properties like position or type.
- Option d (optical axis) refers to a reference line through the center of the lens and doesn’t change based on object distance.
Thus, the most crucial factor determining the image characteristics in a convex lens system is the object’s distance from the lens.
