Question 1

A person is standing 2 meters in front of a plane mirror. What is the distance between the person and their image formed by the mirror?

Accepted Answer

$$4\ \mathrm{m}$$

Question 2

A concave mirror has a radius of curvature $$R = 40\ \mathrm{cm}. $$What is its focal length?

Accepted Answer

$$20\ \mathrm{cm}$$

Question 3

An object is placed $$30\ \mathrm{cm} in $$front of a convex mirror with a focal length $$f = -15\ \mathrm{cm}. $$Where is the image formed?

Accepted Answer

$$s' = -10\ \mathrm{cm}$$

Question 4

A fish is $$20\ \mathrm{cm}$$ below the surface of water ($$n_{water} = 1.33). To an $$observer looking vertically down from above the water, at what depth does the fish appear to be?

Accepted Answer

$$15.0\ \mathrm{cm}$$

Question 5

A thin lens has radii of curvature $$R_1 = +10$$\ \mathrm{cm}$$ and R_2$ = -10\ \mathrm{cm}$$, and is made of glass with $$n = 1.5. $$What is its focal length?

Accepted Answer

$$f = 10\ \mathrm{cm}$$

Question 6

A person with myopia (nearsightedness) has a far point at $$2\ \mathrm{m}. $$What lens power (in diopters) is needed to correct their vision for distant objects?

Accepted Answer

$$-0.5\ \mathrm{D}$$

Question 7

A magnifying glass has a focal length of $$5\ \mathrm{cm}. $$What is its angular magnification when the eye is relaxed (focused at infinity)?

Accepted Answer

$$M = 5$$

Question 8

In a compound microscope, the objective lens has $$f_1 = 1$$\ \mathrm{cm}$$ and the eyepiece has f_2$ = 2.5\ \mathrm{cm}. $$The image formed by the objective is $$s_1$$' = 16\ \mathrm{cm}$$ from the objective. What is the total angular magnification?

Accepted Answer

$$M = 160$$

Question 9

In Young’s double-slit experiment, the slit separation is $$0.5\ \mathrm{mm}$$, the screen is $$2\ \mathrm{m}$$ away, and the light has wavelength $$500\ \mathrm{nm}. $$What is the distance between adjacent bright fringes?

Accepted Answer

$$2.0\ \mathrm{mm}$$

Question 10

A thin film of oil ($$n = 1.25) $$floats on water ($$n = 1.33). $$What is the minimum nonzero thickness for constructive interference in reflected light (assume $$\$$lambda_0$$ = 600\ \mathrm{nm} in $$air)?

Accepted Answer

$$t = 240\ \mathrm{nm}$$

Question 11

A single slit of width $$0.1\ \mathrm{mm} is $$illuminated with light of wavelength $$500\ \mathrm{nm}. $$What is the angular position of the first dark fringe?

Accepted Answer

$$	heta = 0.286$$^{\circ}$$

Question 12

A diffraction grating has $$5000$$ lines per centimeter. What is the angular position of the first-order maximum for light of wavelength $$600\ \mathrm{nm}$$?

Accepted Answer

$$	heta = 17.5$$^{\circ}$$

Question 13

Which of the following statements about interference and diffraction is correct?

Accepted Answer

Both interference and diffraction are consequences of the superposition of waves and Huygens’s principle.

Question 14

A soap film ($$n = 1.33) in $$air is illuminated with white light. What is the minimum thickness for constructive interference in the reflected light for $$\$$lambda_0$$ = 532\ \mathrm{nm}$$?

Accepted Answer

$$t = 100\ \mathrm{nm}$$

Question 15

A person with hyperopia (farsightedness) has a near point at $$100\ \mathrm{cm}. $$What lens power (in diopters) is needed to correct their near point to $$25\ \mathrm{cm}$$?

Accepted Answer

$$+3.0\ \mathrm{D}$$

Question 16

A lens forms a real, inverted image that is twice the size of the object. If the object is $$30\ \mathrm{cm}$$ from the lens, what is the image distance?

Accepted Answer

$$s' = 60\ \mathrm{cm}$$

Question 17

In a two-source interference experiment, the path difference between the two waves at a certain point is $$1.5\lambda. $$What type of interference occurs at that point?

Accepted Answer

Destructive interference

Question 18

A nonreflective coating is applied to a glass lens ($$n = 1.5) $$for light of wavelength $$600\ \mathrm{nm} in $$air. What is the minimum thickness of the coating ($$n = 1.2) to $$minimize reflection?

Accepted Answer

$$t = 125\ \mathrm{nm}$$

Question 19

A single slit of width $$0.2\ \mathrm{mm} is $$illuminated by light of wavelength $$600\ \mathrm{nm}. If $$the screen is $$2\ \mathrm{m}$$ away, what is the distance from the center to the first dark fringe?

Accepted Answer

$$6.0\ \mathrm{mm}$$

Geometric Optics, Optical Instruments, and Interference & Diffraction: Study Notes

Study Guide - Practice Questions

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