Skip to main content
Back

Thin Lens And Lens Maker Equations quiz #1

Control buttons has been changed to "navigation" mode.
1/10

Terms in this set (10)

  • If the thin-lens equation is 1/s + 1/s' = 1/f, what is the equation for the focal length f in terms of the object distance s and the image distance s'?
    The focal length f is given by f = 1 / (1/s + 1/s').
  • What is the meaning of the 'length of the lens' in a camera, and how is it related to the focal length?
    In the context of cameras, the 'length of the lens' typically refers to the focal length, which is the distance from the lens to the image sensor where parallel rays converge to a point. The focal length determines the magnification and field of view of the camera.
  • A lens has a refractive power of 20 diopters. What is its focal length?
    The focal length f (in meters) is the reciprocal of the power in diopters: f = 1/20 = 0.05 meters, or 5 centimeters.
  • Which type of lens always produces a virtual image?
    A diverging lens (such as a biconcave or plano-concave lens) always produces a virtual image.
  • How does immersing a lens in water (with index of refraction n_water = 1.3) affect its focal length, and what equation is used to calculate the new focal length?
    When a lens is immersed in water, its focal length changes because the difference in refractive indices between the lens material and the surrounding medium changes. The lens maker equation is used: 1/f = (n_lens/n_water - 1) [1/R1 - 1/R2], where n_lens is the index of the lens, n_water is the index of water, and R1 and R2 are the radii of curvature of the lens surfaces.
  • When using the lens equation, what sign does the image distance have for a virtual image?
    For a virtual image, the image distance (s') is negative when using the lens equation.
  • When using the lens equation, what sign does the object distance have for a real object?
    For a real object, the object distance (s) is positive when using the lens equation.
  • What is the function of a thin lens with a focal length of 6.00 cm when used as a simple magnifier?
    A thin lens with a focal length of 6.00 cm, when used as a simple magnifier, acts as a converging lens to produce a magnified, virtual, and upright image of an object placed within its focal length.
  • True or false: The quantities di (image distance) and do (object distance) are measured from the focal point of a lens or mirror.
    False. The image distance (di) and object distance (do) are measured from the center of the lens or mirror, not from the focal point.
  • What determines whether a lens is classified as converging or diverging based on its shape?
    A lens is converging if it is thickest in the middle and thinnest at the edges, while it is diverging if it is thinnest in the middle and thickest at the edges. This classification is based on the physical shape of the lens.