EM Waves, Polarization, Thin-Film Interference
Diffraction
Reflection, Refraction
Convex, Concave lenses
Two-lens Systems
(not on Midterm 2!!!)
100

When light experiences a π (pi) phase shift upon reflection, it is reflecting off a medium with a ____ index.

higher 

100

In an experiment with a diffraction grating, how would the bright fringes be affected if we increase the number of slits N?

Bright fringes become narrower (second midterm practice q.2)

100

What is Snell's Law equation?

n1sin θ1=n2sin θ2

100

A concave mirror is a mirror in which the edges curve ____ the light source.

towards

100

For a multi-lens system, the image of the ____ acts as the object for the second lens.

first lens (Feb 21 slides)

200

To polarize an electromagnetic wave in the vertical direction, one should set up a series of parallel conducting paths in the ______ direction.

Horizontal (practice midtern q1)

200

In an experiment with a diffraction grating, how would the bright fringes be affected if we increase the distance between the slits d?

Bright fringes will move closer together (second practice midterm q.3)

200

Under what condition is there no critical angle and no TIR?

When n2>n1 (Feb12 slides)
200

The radius is (negative or positive) for concave mirror.

Positive (Feb 19 slides)

200

Angular size of an object allows closer objects to appear ____(smaller or larger)?

Larger (Feb 21 slides)

300

True or False: The speed of light becomes smaller after it is reflected.

False (practice midterm q7)

300

Light from a helium-neon laser (λ = 633 nm) passes through a narrow slit and is seen on a screen 2.0 m behind the slit. The first minimum in the diffraction pattern is 1.2 cm from the middle of the central maximum. How wide is the slit?

0.11m (Feb 7 slides)

300

Crossing a boundary into a material with a ____ index of refraction causes the ray to bend away from the normal.

Lower (Feb12 slides)
300

 An object with a height of 5 cm is placed 15 cm in front of a concave mirror that has a focal length of 20 cm. What is the height of the resulting image?

20cm (practice midterm q13)

300

An object is placed right at the focal point of a magnifier. How does the apparent size of the image depend on where the eye is placed relative to the lens?

The apparent size is independent of the eye position (Feb 21 slides)

400

Unpolarized sunlight with intensity 1400 W m−2 passes through a polarizing filter with its axis vertical, then through a second polarizing filter with its axis at an angle θ to the vertical. If you want to reduce the intensity of the sunlight to 1/10 of its initial value of 1400 W m−2, what angle θ should you choose for the second filter?

63 (practice midterm q8)

400

White light passing through a feather is spread into a rainbow diffraction pattern by the feather’s barbules—small, evenly spaced structures as shown in the figure. If they are spaced at 50 per mm, what is the first-order diffraction angle for blue light of 450 nm and red light of 650 nm?

Blue = 1.3, Red = 1.9 (Feb 7 slides)

400

The figure shows a laser beam deflected by a 30°-60°-90° prism. What is the prism’s index of refraction?

1.59 (Feb12 slide example 1 of 3)

400

For a dental mirror, in which the dentist wants to see a magnified, upright image of the tooth, the mirror should be ____ (concave or convex), with the mirror placed ____ (closer or farther) to the tooth than the focal length.

concave, closer (practice midterm q6)

400

If a person views a bug with magnifying lens having a 12.5 cm focal length, then the lateral magnification would be _____?

∞ (Feb 21 slides)

500

A thin film of oil (n = 1.25) floats on water. What is the thinnest film (but not zero) that will produce a strong reflection of light with a wavelength of 525 nm in air, thus making the oil sheen appear to be green?

210nm (practice midterm q10)

500

Light from a sodium lamp passes through a diffraction grating with 1000 slits per mm. The interference pattern is viewed on a screen 1.00 m behind the grating. Two bright yellow fringes are visible at 72.88 cm and 73.00 cm from the central maximum. What are the wavelengths of these two fringes?

589nm , 589.6nm (Feb 7 slides)

500

Aaliyah is walking a shallow, clear bay in still water just over her knees. When she looks at her feet in the sand, they appear closer to her than usual. Normally her feet are 1.6 m from her eyes. How far away do her feet appear when they are under 0.60 m of water?

1.45m (Feb12 slides ex 4 of 4)

500

A 3.0-cm-high object is located 20 cm in front of a concave mirror that has a focal length of 40 cm. Determine the position, orientation, and height of the image.

Image is 6cm tall, upright (Feb 19 slides)

500

A pathologist inspects a sample of 7-µm-diameter human blood cells under a microscope. She selects a 40× objective and a 10× eyepiece. What size object, viewed from 25 cm, has the same apparent size as a blood cell seen through the microscope?

~ 3mm (Feb 21 slides)

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