Light and Optics (CH8)

Question 1

Nearsightedness (aka the individual sees best up close, therefore far objects are difficult to see) is corrected by what type of lens and what is this medical condition named?

Answer 1

Myopia is usually corrected with a concave lens (aka diverging lens).

Question 2

Farsightedness (aka the individual sees far distances best, therefore close objects are difficult to see) is corrected by what type of lens and what is this medical condition named?

Answer 2

Hyperopia is usually corrected with a convex lens (aka converging lens).

Question 3

In regards to mirrors, what is diverging and converging?

Answer 3

Mirrors are the opposite of lenses (therefore a concave mirror = converging, and convex mirror = diverging).

Question 4

In regards to plus and minus signs for mirrors and lenses, what is consistent with focal point and radius of curvi?

Answer 4

Converging lenses are always positive (+) and diverging lenses are always negative (-).

Question 5

In regards to plus and minus signs for mirrors and lenses, what is consistent with image length?

Answer 5

Real images are positive (+) and virtual images are negative (-).

Question 6

For mirrors, what determines if the image is real or virtual?

Answer 6

• REAL: image in front of mirror
• VIRTUAL: image is behind mirror
• UV NO IR*

Question 7

For lenses, what determines if the image is real or virtual?

Answer 7

• REAL: image is on opposite side of lens from light source

- VIRTUAL: image is on the same side of lens as light source

Question 8

For both lenses and mirrors, how do signs affect object distance?

Answer 8

If the object is in front it is positive (+), but if it is behind it is negative (-).

Question 9

For both lenses and mirrors, how do signs affect magnification?

Answer 9

• If the image is upright, it is positive (+).

- If the image is inverted, it is negative (-).

Question 10

What is the visible spectrum of light from red to violet?

Answer 10

700 nm to 400 nm