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Worksheet: The Simple Magnifier


You view a mountain with a magnifying glass of focal length 𝑓 = 1 0 cm. What is the magnification?

  • A3.4x
  • B2.9x
  • C3.7x
  • D2.5x
  • E4.0x


A magnifying glass produces an angular magnification of 4.5x when used by a person with a near point of 18 cm. What is the maximum angular magnification obtained with the lens by a person with a near point of 45 cm?

  • A8.8x
  • B8.5x
  • C9.3x
  • D9.8x
  • E9.5x


How far should you hold a 2.1-cm-focal length magnifying glass from an object to obtain a magnification of 10x? Assume you place your eye 5.0 cm from the magnifying glass.


An object viewed with the naked eye subtends a 6 . 0 ∘ angle. If you view the object through a 10x magnifying glass, what angle is subtended by the image formed on your retina?


What will be the angular magnification of a convex lens with the focal length 2.5 cm?

  • A13x
  • B10x
  • C15x
  • D11x
  • E16x


A doctor examines a mole with a 10.0 cm focal length magnifying glass, which is held 12 cm from the mole. What magnification does the lens produce?


A magnifying glass forms an image 10 cm on the opposite side of the lens from the object, which is 10 cm away. What is the magnification of this lens for a person with a normal near point if their eye 12 cm from the object? The lens-to-retina distance is 2.00 cm.

  • A βˆ’ 2 . 5 x
  • B βˆ’ 1 . 6 x
  • C βˆ’ 2 . 9 x
  • D βˆ’ 2 . 1 x
  • E βˆ’ 3 . 3 x


A magnifying lens with a focal length of 14.0 cm is held 4.00 cm from an eye and the object is 13.0 cm from the eye. What is the magnification of the lens?

  • A 9.25x
  • B 12.3x
  • C 8.33x
  • D 10.7x
  • E 7.00x


While outdoors on a sunny day, a student holds a large convex lens of radius 5.0 cm vertically above a sheet of paper, producing a bright spot of light on the paper 2.0 cm in radius. The magnitude of the electric field within the bright spot of light is 𝐸  and that of the sunlight leaving the side of the lens facing the paper is 𝐸  . Find the ratio of 𝐸  to 𝐸  .


Find the angular magnification of an image by a magnifying glass of 𝑓 = 6.3 cm if the object is placed 𝑑 o = 5.8 cm from the lens and the lens is close to the eye.


A magnifying glass produces a magnification of 4.00 when held at a distance of 6.00 cm from a coin. What is the focal length of the magnifying glass?


What is the angular magnifier of a binocular that has a focal length of 1.9 cm for the eyepiece and a focal length of 9.0 cm for the objective?


If the image formed on the retina subtends an angle of 3 0 ∘ and the object subtends an angle of 5 . 0 ∘ , what is the magnification of the image?

  • A 5 . 6 π‘₯
  • B 5 . 0 π‘₯
  • C 6 . 5 π‘₯
  • D 6 . 0 π‘₯
  • E 6 . 9 π‘₯


You view an object by holding a 3.50 cm focal length magnifying glass 10.0 cm away from it. How far from your eye should you hold the magnifying glass to obtain a magnification of 10.0x?