Reflection & Mirrors
What is the law that states the angle of incidence equals the angle of reflection?
The Law of Reflection
What kind of lens converges light rays to a focal point?
Double convex (converging) lens
What quantities are related by the formula v=λ⋅f ?
Wave speed (v), wavelength (λ), and frequency (f).
Which part of the eye is a transparent, dome-shaped tissue that helps focus incoming light?
Cornea
Who used a prism to show that white light is made of different colours (rainbow)?
Sir Isaac Newton.
Name the type of reflection that occurs on a smooth surface producing a clear image.
Specular (regular) reflection.
What is the main difference between a refracting telescope and a reflecting telescope?
Refractor uses lenses; reflector uses mirrors.
Which region of the electromagnetic spectrum has wavelengths roughly between 400 nm and 700 nm? (Hint: we are able to see it)
Visible light.
What are the two main types of photoreceptor cells in the retina and what is a key difference in their function?
Rods (sensitive in low light, no color) and cones (color vision, less sensitive).
Name two early inventors or scientists associated with the development of microscopes or eyeglasses from the unit.
Hans & Zacharias Janssen (microscope), Alessandro della Spina / Salvino D'Armate (eyeglasses), Antonie van Leeuwenhoek (microscopes).
For a concave mirror, where do parallel incoming rays meet after reflection?
At the focal point
Explain what happens to the image formed by a double convex lens when the object is placed between the lens and its focal point.
A virtual, upright, enlarged image appears on the same side as the object
Explain what happens to the image formed by a double convex lens when the object is placed between the lens and its focal point.
Prism refracts different wavelengths by different amounts so colors spread into a spectrum because each color has a different wavelength/speed in the glass.
Define myopia.
Myopia: image focuses in front of the retina, causes nearsightedness.
Describe Michelson’s contribution to measuring a property of light and give his measured value (approximate) from the unit.
Michelson measured the speed of light ~299,798 km/s.
Describe how the image appears (orientation and size) when an object is located beyond the center of curvature of a concave mirror.
Inverted (upside down) and smaller (if beyond center of curvature)
Name the type of telescope (from the unit) that uses both lenses and mirrors and give one advantage of that compound design.
Compound; advantage: compact with long focal length and versatile.
Define refraction using the idea of light moving between media of different density and mention which historical scientist is credited with describing the bending of light from air to water.
Refraction = bending toward the normal when entering a denser medium; Ptolemy described bending from air to water (refraction).
Explain how the ciliary muscle helps the eye focus on near objects (use the concept of lens shape).
Ciliary muscle contracts to make the lens more convex (thicker), increasing its refractive power for near focus
Identify three modern technologies that rely on optics and give a one-sentence explanation for each (e.g., fiber optics, LASIK, cameras).
Fiber optics — transmit data as light pulses for high-speed communication; LASIK — uses lasers to reshape the cornea to correct vision; Cameras — use lenses to focus light onto a sensor to form images.
List three real-world applications of concave mirrors and explain briefly why concave mirrors are used in each.
Sample answers — satellite dishes (focus signals), headlights (collimate light), makeup mirrors (magnify); explanation: concave shape focuses incoming rays to a point.
A telescope uses a primary mirror with focal length 1200 mm. If parallel rays focus at that focal point, explain briefly how changing the mirror curvature would affect the focal length and image formation.
Sample answers — satellite dishes (focus signals), headlights (collimate light), makeup mirrors (magnify); explanation: concave shape focuses incoming rays to a point.
Describe total internal reflection and give one example of where it is used in optical technology.
Total internal reflection occurs when light from a denser medium hits a boundary at an angle greater than the critical angle and reflects entirely; used in fiber optic cables.
The retina receives an inverted image. Explain briefly how the brain handles this to give us upright vision.
The brain receives inverted signals from the retina and interprets them so we perceive scenes upright (neural processing remaps orientation).
Describe Roemer’s method for estimating the speed of light and explain why his measurement differed from the modern accepted value.
Roemer measured variations in Jupiter’s moon Io eclipses to infer light’s finite speed; his value (~227,000 km/s) was lower than the true value because of measurement limitations and less precise distance/time data.