Download Electromagnetic Spectrum Practice Problems

Electromagnetic Spectrum Practice Problems
1. Radio station WKLB in Boston broadcasts at a frequency of 99.5 MHz. What is the wavelength of the radio
waves emitted by WKLB?
2. Radio station KSON in San Diego broadcasts at both 1240kHz(AM) and 97.3 MHz (FM). Which signal has
the longer wavelength? What are the wavelengths of the signals?
3. Microwave ovens emit waves of about 2450 MHz. What is the wavelength of this light?
4. When you look at a distant star or planet, you are looking back in time. How far back in time are you
looking when you observe Pluto through the telescope from a distance of 5.91 x 1012 m?
5. If a person could travel at the speed of light, it would still take 4.3 years to reach the nearest star, Proxima
Centauri. How far away, in meters, is Proxima Centauri?
Electromagnetic Spectrum Practice Problems
1. Radio station WKLB in Boston broadcasts at a frequency of 99.5 MHz. What is the wavelength of the radio
waves emitted by WKLB?
2. Radio station KSON in San Diego broadcasts at both 1240kHz(AM) and 97.3 MHz (FM). Which signal has
the longer wavelength? What are the wavelengths of the signals?
3. Microwave ovens emit waves of about 2450 MHz. What is the wavelength of this light?
4. When you look at a distant star or planet, you are looking back in time. How far back in time are you
looking when you observe Pluto through the telescope from a distance of 5.91 x 1012 m?
5. If a person could travel at the speed of light, it would still take 4.3 years to reach the nearest star, Proxima
Centauri. How far away, in meters, is Proxima Centauri?
6. When you go out in the sun, it is the ultraviolet light that gives you your tan. The pigment in your skin
called Melanin is activated by the enzyme tyrosinase, which has been stimulated by ultraviolet light. What
is the wavelength of this light if it has a frequency of 7.89 x 1014 Hz?
7. IRAS, the Infrared Astronomy Satellite launched by NASA in 1983, had a detector that was supercooled to
enable it to measure infrared or heat radiation from different regions of space. What is the frequency of
infrared light that has a wavelength of 1.00 x 10-6 m?
8. Yellow light has a wavelength of 556 nm. What is its frequency?
9. Laboratory workers often estimate the distance light travels in a certain time by remembering the
approximation “light travels one foot in one nano-second”. How far in meters does light actually travel in
one nanosecond (1x10-9 s)? Check your answer with a meter-stick (compare your answer to one foot).
10. The distance to the moon can be found with the help of mirrors left on the moon by astronauts. A pulse of
light is sent to the moon and returns to Earth in 2.562 seconds. Calculate the distance to the moon.
6. When you go out in the sun, it is the ultraviolet light that gives you your tan. The pigment in your skin
called Melanin is activated by the enzyme tyrosinase, which has been stimulated by ultraviolet light. What
is the wavelength of this light if it has a frequency of 7.89 x 1014 Hz?
7. IRAS, the Infrared Astronomy Satellite launched by NASA in 1983, had a detector that was supercooled to
enable it to measure infrared or heat radiation from different regions of space. What is the frequency of
infrared light that has a wavelength of 1.00 x 10-6 m?
8. Yellow light has a wavelength of 556 nm. What is its frequency?
9. Laboratory workers often estimate the distance light travels in a certain time by remembering the
approximation “light travels one foot in one nano-second”. How far in meters does light actually travel in
one nanosecond (1x10-9 s)? Check your answer with a meter-stick (compare your answer to one foot).
10. The distance to the moon can be found with the help of mirrors left on the moon by astronauts. A pulse of
light is sent to the moon and returns to Earth in 2.562 seconds. Calculate the distance to the moon.
Electromagnetic Spectrum Practice Problems
Answers:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
c
3.0 x108
 
 3.02m
6
f 99.5x10
  242m  1240 _ is _ longer
  3.08m
0.122 m
19,700 s
4.07 x 1016 m
3.80 x 10-7 m
3 x 1014 Hz
f = 5.4 x 1014 Hz; T = 1.85 x 10-15 s
0.3 m
3.84 x 108 m
11. 6.30 x 10-14 m