lens

• The refraction of light is the bending of light as it passes from one medium to another.
• A medium is a substance that can transfer energy from one location to another and it can be a solid, a liquid, or a gas.
• There are three mediums involved in the activity 7, these are glass (a solid), water (a liquid), and air (a gas) before the light reaches your eyes.
• During the experiment, the light traveled from the image through the air, then through the glass cup into the water, and finally out of the glass cup and into the air once more before it reached our eyes.
• The light paths cross and the image appears to be flipped horizontally.
• The bending of light occurs due to the differences in the index of refraction of a medium.
• As it refracts, the velocity of the light is altered, its wavelength increases or decreases, but its frequency remains constant.
• Light is refracted in the boundary at an angle.
• A lens is a shaped transparent material that refracts light to create an image.
• There are two main types of lenses, the converging lens, and the diverging lens.
• A converging lens is a lens that is thicker in the middle than the edges, also known as a convex lens.
• A diverging lens or a concave lens is a lens that is thinner at the middle than the edges.
• When parallel light rays will pass through the converging lens or convex lens, it will bend or refract at the center of the lens and converge at the other side forming a real focus.
• When parallel light rays will pass through the diverging lens or concave lens, it will refract at the center of the lens and the refracted rays are diverge.
• Notice that there is no intersecting of the refracted rays on the opposite side of the light source, but if you extend the refracted rays to the location of the light source you will notice that it will form focus and this focus is virtual.