# Experimenting with a Diverging Lens: Discovering the Focal Point

• SwAnK
In summary, the conversation is about an experiment using a diverging or convex lens to produce different images according to the focal point. The experimenter found the focal length and set up the lens and light source at that distance, using paper as a screen. The question is asked about how to do the same experiment with a diverging lens. The response is that it is not possible to produce images on a screen with a diverging lens, but methods such as parallax can be used to locate virtual images.
SwAnK
Hey all, I recently did an experiment using a diverging or convex lens, to produce different images according to the focal point. For the experiment I found the focal length, and set up the lens and light source at that distance. I used just paper for a screen to produce the real images created.

MY question: How could you do this experiment with a diverging lens?

Could you not do the same thing set it up in that manner, and place the lens at different spots according to the focal point? and when its infront of the focal point it produces an upright virtual, smaller image right?? just checking.

thanx!

Is this a double convex lens, because a convex lens is a converging one, not a diverging one.

As for the experiment. You could as a experiment make all of the predictions of what kind of image would form at different points by your lens equations and then check them manually.

no like double concave, yes that's basically what i did for the converging lens, but would the same process i used work with double concave?

With the same experiment you can't do that with a divergin lense because a diverging lense will not produce an image on a screen so you can't find the focal point that way. This is based on my knowledge, I recently finished this unit(a month ago) and mixed up 'diverging' and 'converging' on my test so I mostlikely wrong.

SwAnK said:
Hey all, I recently did an experiment using a diverging or convex lens, to produce different images according to the focal point. For the experiment I found the focal length, and set up the lens and light source at that distance. I used just paper for a screen to produce the real images created.

MY question: How could you do this experiment with a diverging lens?

Could you not do the same thing set it up in that manner, and place the lens at different spots according to the focal point? and when its infront of the focal point it produces an upright virtual, smaller image right?? just checking.

thanx!

As others have noted, you cannot form images from the diverging lens on a screen. These images are referred to as virtual images because the light never gets to where these images are located. Instead, light is made to appear as if it were originating at these images. One way to locate these images is to use parallax. You need to use an object that you can see outside the edge of the lens that you can place the same distance from the lens as the virtual image. You know they are the same distance from the lens if moving your head from side to side leaves this object and the virtual image aligned. You can then measure the distance of the object to find the image distance.

## 1. What is a diverging lens?

A diverging lens is a type of lens that is thicker at the edges and thinner in the middle. It causes light rays to spread out, or diverge, when passing through it.

## 2. How is the focal point of a diverging lens determined?

The focal point of a diverging lens can be determined by tracing the light rays that pass through the lens. The point where the rays intersect after passing through the lens is the focal point.

## 3. What are some common uses for a diverging lens?

Diverging lenses are commonly used in glasses or contact lenses for people with nearsightedness, as they help to spread out the light rays before they reach the eye. They are also used in a variety of optical instruments, such as cameras and projectors.

## 4. How does the focal length of a diverging lens affect its performance?

The focal length of a diverging lens determines the amount of divergence of the light rays passing through it. A shorter focal length will result in a larger divergence, while a longer focal length will result in a smaller divergence.

## 5. Can the focal point of a diverging lens be changed?

No, the focal point of a diverging lens is determined by its shape and cannot be changed. However, the position of the lens can be adjusted to change the location of the focal point in relation to the lens.

• Introductory Physics Homework Help
Replies
4
Views
747
• Introductory Physics Homework Help
Replies
7
Views
2K
• Introductory Physics Homework Help
Replies
1
Views
954
• Introductory Physics Homework Help
Replies
20
Views
2K
• Introductory Physics Homework Help
Replies
3
Views
1K
• Introductory Physics Homework Help
Replies
1
Views
1K
• Introductory Physics Homework Help
Replies
10
Views
3K
• Introductory Physics Homework Help
Replies
4
Views
1K
• Introductory Physics Homework Help
Replies
14
Views
2K
• Introductory Physics Homework Help
Replies
1
Views
4K