"Lens" Common optical instruments PPT courseware

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"Lens" Common optical instruments PPT courseware

New knowledge exploration

1. Lens

The surfaces of glass components such as cameras, microscopes, and spectacle lenses are all part of the sphere, called lenses.

1. Convex lens

Concept: A lens that is thick in the middle and thin at the edges is called a convex lens.

Convex lens main optical axis, focus, focal length

Main optical axis: The straight line C1C2 passing through the two novelties is called the main optical axis.

Focus: The point at which light rays parallel to the main optical axis converge after passing through a convex lens is called the focus, represented by the symbol F.

Focal length: The distance from the focus to the optical center is called the focal length, represented by the symbol f.

The effect of convex lens on light

The converging effect of convex lenses on light.

2. Concave lens

A lens that is thin in the middle and thick at the edges is called a concave lens.

Concave lens main optical axis and focus

Virtual focus: The reverse extension line of the light rays parallel to the main optical axis that diverged after passing through the concave lens intersects at a point called the virtual focus, represented by the symbol F.

Focal length: The distance from the focus to the optical center is called the focal length, represented by the symbol f.

The divergent effect of concave lenses on light.

2. Light passing through the optical center of the lens

Conclusion: The direction of light propagation through the optical center does not change.

3. How to measure the focal length of a convex lens

Focal length measurement by parallel light convergence method: Place the convex lens facing the sun, place a piece of white paper on the other side of the lens, change the distance between the lens and the white paper until you find the smallest and brightest spot on the white paper, use the scale The distance from the light spot to the lens measured with a ruler is the focal length.

Class exercises

1. Lenses are made using the ( ) law of light. There are two types of lenses: one type is a lens that is thicker in the middle than the edge and is called ( ), such as ( ) lens; the other type is a lens that is thinner in the middle than the edge is called ( ). , such as () lens.

2. The optical center is roughly at the center of the lens, and the straight line passing through the optical center and the center of the spherical surface is called the lens ().

3. Convex lenses have ( ) effects on light, and concave lenses have ( ) effects on light.

4. When parallel light passes through a convex lens, it will converge to a point on the main optical axis. This point is called ( ) of the convex lens. The distance from ( ) to the optical center is called ( ). A lens has two ( ).

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For more information about the "Lens Common Optical Instruments" PPT courseware, please click the Lens ppt Common Optical Instruments ppt tag.

"Lens and Vision" PPT download:

"Lens and Vision" PPT Download Part One: Pre-class Thoughts 1. How to roughly measure the focal length of a convex lens? Face the convex lens to the sun, use a piece of white paper as a light screen on the other side of the convex lens, so that the convergence point of the light appears on the light screen, and measure it with a scale.

"Lens and Vision" PPT courseware:

"Lens and Vision" PPT courseware Part 1: Think about it 1. Have you ever encountered or used lenses in your life? Myopia glasses, magnifying glass, telescope ------- 2. What are the common characteristics of different lenses? Materials (glass, resin, crystal, etc.) various...

"Lens and Vision" PPT:

"Lens and Vision" PPT Part One Content: Lenses in Life Observe the following lenses and talk about the characteristics of these lenses Thick in the middle Lenses with thin edges Convex lenses Thin in the middle Lenses with thick edges Concave lenses... ... Lens and vision PPT, second...

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Update Time: 2024-07-04

This template belongs to Physics courseware Beijing Normal University eighth grade physics volume 2 industry PPT template

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