Optics Answers

A student is only able to read the lecture notebook when it is held at 65.00cm from his eyes. What focal length and power must the lenses of his reading glasses have to bring his near point to the normal value

A light ray travelling from glass to air undergoes refraction. Calculate the angle of refraction to the nearest whole number if the incidence angle is 30° and the refractive for air and glass are 1.0 and 1.5 respectively.

A compound microscope consists of objective and eye piece lens of focal length 0.50cm and 1.00cm respectively. An object is placed 0.55cm from the objective lens and the final image is formed at infinity. Calculate the magnifying power of the glass and the tube L.

You can’t see clearly underwater with the naked eye, but you can if you wear a face mask or goggles (with air between your eyes and the mask or goggles). Why is there a difference? Could you instead wear eyeglasses (with water between your eyes and the eyeglasses) in order to see underwater? If so, should the lenses be converging or diverging? Explain.

If a piece of photographic film is placed at the location of a real image, the film will record

the image. Can this be done with a virtual image? How might one record a virtual image?

A spherical air bubble in water can function as a lens. Is it a converging or diverging lens?

How is its focal length related to its radius?

The bottom of the passenger-side mirror on your car notes, “Objects in mirror are closer than they appear.” Is this true? Why?

You may have noticed a small convex mirror next to your bank’s ATM. Why is this mirror

convex, as opposed to flat or con- cave? What considerations determine its radius of curvature?

In the figure above, q₁ = 6.53 nC, q₂ = 13.1 nC, and q₃ = 13.1 nC. If the net force on q₁ is 0, then what would q be?

Can water waves be reflected and refracted? Give examples. Does Huygens’s principle apply to water waves? Explain.