13.5 Optical Instruments

• Optical instruments use lenses and/or mirrors
• What type of lens is used in microscopes to magnify small samples?

  Short focal length lens
• Which optical instrument uses only lenses for its operation?

  Microscope
• What is the function of the iris in the eye?

  Adjusts pupil size
• What is the magnification of a simple magnifier given by?

  Ratio of apparent to actual size
• Simple magnifiers use complex lens/mirror systems to gather more light for magnification.

  False
• Telescopes use a large objective lens or mirror to magnify distant objects.


  True
• Cameras use a lens to focus light onto a light-sensitive surface
• Steps in the process of vision in the eye:

  1️⃣ Light enters through the pupil

  2️⃣ The lens focuses light onto the retina

  3️⃣ The retina converts light into electrical signals

  4️⃣ Signals are sent to the brain
• A simple magnifier uses a convex lens to create an enlarged, upright, virtual image.

  True
• What happens to light rays when an object is placed within the focal length of a lens in a simple magnifier?

  They are refracted
• What type of lens is used in a simple magnifier?

  Convex lens
• What are optical instruments defined as?

  Devices using lenses/mirrors
• Microscopes use a short focal length lens to greatly magnify small samples.


  True
• The lens, pupil, and iris work together to regulate light and focus it onto the retina.


  True
• A simple magnifier creates an image on the opposite side of the lens from the object.

  False
• What does the eyepiece lens in a compound microscope do?

  Magnifies the image
• Telescopes use both lenses and mirrors to magnify distant objects.

  True
• What is the primary purpose of a telescope?

  To view distant objects
• Telescopes use a large objective lens or mirror to gather more light
• What are optical instruments used for?

  Manipulating light to form images
• Match the optical instrument with its purpose:

  Telescopes ↔️ View distant objects

  Microscopes ↔️ View small objects in detail

  Cameras ↔️ Capture images
• Telescopes always use lenses to view distant objects.

  False
• The lens of the eye focuses light onto the retina
• The magnification power of a convex lens is determined by its focal length
• The magnification of a simple magnifier is the ratio of the apparent size of the object to its actual
• Steps in the working mechanism of a simple magnifier

  1️⃣ The focal length of the lens determines magnification power

  2️⃣ The object is placed within the focal length

  3️⃣ The lens refracts light rays

  4️⃣ The object appears larger to the eye
• Match the optical instrument with its purpose:

  Telescopes ↔️ View distant objects

  Microscopes ↔️ View small objects

  Cameras ↔️ Capture images
• What is the function of the eye's lens?

  Focuses light on retina
• What type of image is created by a simple magnifier?

  Enlarged, upright, virtual
• What type of lens is used in simple magnifiers?

  Convex lens
• The objective lens in a compound microscope has a short focal length
• What type of lens is used in microscopes to view small objects in detail?

  Short focal length lens
• Optical instruments are essential in fields like biology and medicine.

  True
• The objective lens in a compound microscope has a short focal length to gather more light.


  True
• Telescopes use a large objective lens or mirror to gather more light
• The retina converts light into electrical signals
• Match the component of a simple magnifier with its function:

  Convex Lens ↔️ Bends light rays to form an enlarged image

  Focal Length ↔️ Determines the magnification power
• Simple magnifiers use complex lens systems to gather more light.

  False
• Why does the objective lens in a compound microscope have a short focal length?

  To gather more light