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Thin Lens. Chapter 15.2. Bending of Light. Any transparent object that is curved with affect the path of light rays. Ex: Glass bottle full of water will affect the image of an object.
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Thin Lens Chapter 15.2
Bending of Light • Any transparent object that is curved with affect the path of light rays. • Ex: • Glass bottle full of water will affect the image of an object. • Your eye’s muscles expand and contract causing the lens in your eye to change shape and therefore allow people to focus on different objects.
Lens • Lens – A transparent object that refracts light rays, causing them to converge or diverge to create an image.
Converging Lens • Converging Lens – A lens where the middle part of the lens is thicker than the rim. • Also known as a convex lens.
Diverging Lens • Diverging Lens – A lens where the middle part of the lens is thinner in the middle and thicker around the rim. • Also known as a concave lens.
Focal Length • Each lens has two focal points (F), therefore there are two focal length (f). • A focal length is measured from the focal point to the center of the lens (normal). • The focal points lay on the principal axis.
Converging & Diverging Focal Points • For converging lens, the focal point is located at the point where the rays of light meet at a single point. • For diverging lens, the focal point is located at a point from which the diverged rays appear to originate.
Characteristics of Converging Lens • Image is always real, unless object is in front of the focal point. • Image is always on the opposite side the lens, unless the object is in front of the focal point. • Image is always inverted, unless object is in front of the focal point.
Characteristics of Diverging Lens • Image is always virtual (Imaginary). • Magnification is less than 1. • Image is always upright. • Image is formed on the same side as the object.
Thin-Lens Equation p = Object Distance - Always Positive q = Image Distance - Negative ( Object side of lens) - Positive (Opposite side of Lens) f = Focal Length - Positive (Converging Lens) - Negative (Diverging Lens)
Magnification Equation M = Magnification - Positive (Upright Image) - Negative (Inverted Image) - M>1 (larger Image) M<1 (Smaller Image) h = Object Height h‘ = Image Height p = Object Distance q = Image Distance
Example Problem • An object is placed 30.0cm in front of a converging lens that has a focal length of 10.0cm. Find the image distance and magnification.