Q3.
Is it possible for an electromagnetic wave to travel through a vacuum? Explain
Yes. Electric and magnetic fields exist in otherwise empty space, so an electromagnetic wave consisting of changing electric and magnetic fields can propagate through a vacuum. Unlike mechanical waves, it does not require a medium.
Q9.
A certain pigment absorbs green light, while reflecting blue and red wavelengths. If a surface coated with this pigment is illuminated by white light, what is the color of the light reflected from this surface? Explain.
The surface would appear purple or magenta depending upon the amounts of blue and red light reflected.
Q15.
If two waves start out in phase with each other, but one wave travels half a wavelength farther than the other before they come together, will the waves be in phase or out of phase when they combine? Explain.
They will be out of phase by 180 degrees.
Q21.
Why do lenses having reflective coating appear to have a purplish tinge when viewed in reflected light? Explain.
The antireflective coatings are most effective for wavelengths in the middle of the visible spectrum. At the red or blue ends of the spectrum, the conditions for destructive interference are not met, so some of this light is reflected, giving the lenses a
Q27.
Can a wave on a guitar string be polarized? Explain.
Yes. This is a transverse wave and can be polarized.
E1.
Microwaves used in microwave ovens often have a wavelength of about 30 cm. What is the frequency of these waves?
...
E5.
Light with a wavelength of 500 nm (5 � 10?7 m) is incident upon a double slit with a separation of 0.4 mm (4 � 10?4 m). A screen is located 2.0 m from the double slit. At what distance from the center of the screen will the first bright fringe beyond
2.5 mm
E9.
An antireflection coating is designed with a thickness of a quarter of the wavelength of the light traveling in the film.
a.
How many wavelengths farther does the light reflected from the bottom surface of the coating travel than that reflected from t
a.
1/2 wavelength
b.
destructive
E11.
When illuminated with light of 600 nm (6 � 10?7 m), the first dark fringe produced by a single slit lies a distance of 1.4 cm from the center of the screen placed 3.0 m from the slit. How wide is the slit?
0.129 mm
SP1.
The visible spectrum of colors ranges from approximately 380 nm in wavelength at the violet end to 750 nm at the far red end.
a.
What are the frequencies associated with these two wavelengths?
b.
When light passes into glass, the speed of light is re
a.
7.9 � 1014 Hz, 4.0 � 1014 Hz
b.
2 � 108 m/s
c.
253 nm, 500 nm