Magnification and Image Formation

Oct 13, 2025 by wbrum.org 108 views

Introduction

In optics, lenses are used to focus light and form images. The type of image formed by a lens depends on several factors, including the type of lens, the position of the object, and the magnification of the lens. In this article, we will explore how to determine the type of image formed by a lens given its magnification.

Magnification and Image Formation

The magnification of a lens is defined as the ratio of the height of the image to the height of the object. It is denoted by the symbol m and is calculated using the following formula:

m = -di/do

where di is the distance of the image from the lens and do is the distance of the object from the lens.

Interpreting the Magnification Value

The sign of the magnification value indicates the type of image formed by the lens. If the magnification value is positive, the image is virtual and upright. If the magnification value is negative, the image is real and inverted.

Determining the Type of Image

Given the magnification value m = -0.6, we can determine the type of image formed by the lens.

If the magnification value is negative, the image is real and inverted.
If the magnification value is between -1 and 0, the image is real and smaller than the object.
If the magnification value is less than -1, the image is real and larger than the object.

Calculating the Magnification Value

To calculate the magnification value, we need to know the distance of the image from the lens and the distance of the object from the lens.

m = -di/do

We can rearrange this formula to solve for di:

di = -m \* do

Determining the Type of Image Formed by the Lens

Given the magnification value m = -0.6, we can determine the type of image formed by the lens.

The magnification value is negative, so the image is real and inverted.
The magnification value is between -1 and 0, so the image is real and smaller than the object.

Conclusion

In conclusion, the type of image formed by a lens depends on its magnification value. If the magnification value is negative, the image is real and inverted. If the magnification value is between -1 and 0, the image is real and smaller than the object. Given the magnification value m = -0.6, the image formed by the lens is a real image that is smaller than the object.

Answer

The correct answer is:

A. A real image that is smaller than the object

References

Hecht, E. (2017). Optics. Pearson Education.
Serway, R. A., & Jewett, J. W. (2018). Physics for Scientists and Engineers. Cengage Learning.
Frequently Asked Questions (FAQs) about Image Formation by Lenses ====================================================================

Q: What is the relationship between magnification and image formation?

A: The magnification of a lens is defined as the ratio of the height of the image to the height of the object. It is denoted by the symbol m and is calculated using the formula m = -di/do, where di is the distance of the image from the lens and do is the distance of the object from the lens.

Q: How do I determine the type of image formed by a lens given its magnification value?

A: To determine the type of image formed by a lens, you need to look at the sign of the magnification value. If the magnification value is positive, the image is virtual and upright. If the magnification value is negative, the image is real and inverted.

Q: What is the significance of the magnification value being between -1 and 0?

A: If the magnification value is between -1 and 0, the image is real and smaller than the object. This means that the image is formed on the same side of the lens as the object, but it is smaller in size.

Q: What is the significance of the magnification value being less than -1?

A: If the magnification value is less than -1, the image is real and larger than the object. This means that the image is formed on the same side of the lens as the object, but it is larger in size.

Q: Can a lens form a virtual image?

A: Yes, a lens can form a virtual image. This occurs when the magnification value is positive, indicating that the image is formed on the same side of the lens as the object, but it is upright and smaller in size.

Q: Can a lens form a real image that is larger than the object?

A: Yes, a lens can form a real image that is larger than the object. This occurs when the magnification value is less than -1, indicating that the image is formed on the same side of the lens as the object, but it is larger in size.

Q: How do I calculate the magnification value of a lens?

A: To calculate the magnification value of a lens, you need to know the distance of the image from the lens and the distance of the object from the lens. The formula for magnification is m = -di/do.

Q: What is the significance of the distance of the image from the lens?

A: The distance of the image from the lens is an important factor in determining the type of image formed by the lens. If the image is formed on the same side of the lens as the object, it is a real image. If the image is formed on the opposite side of the lens from the object, it is a virtual image.

Q: Can a lens form an image that is both real and virtual?

A: No, a lens cannot form an image that is both real and virtual. The type of image formed by a lens is determined by the sign of the magnification value, which is either positive (virtual) or negative (real).

Conclusion

In conclusion, the type of image formed by a lens depends on its magnification value and the distance of the image from the lens. By understanding the relationship between magnification and image formation, you can determine the type of image formed by a lens given its magnification value.