15.1 The Electromagnetic Spectrum
Which type of EM radiation has the shortest wavelengths?
- gamma rays
- infrared waves
- blue light
Which form of EM radiation has the most penetrating ability?
- red light
- gamma rays
- infrared radiation
15.2 The Behavior of Electromagnetic Radiation
To compare the brightness of light bulbs for sale in a store, you should look on the labels to see how they are rated in terms of ____.
What is the wavelength of red light with a frequency of 4.00 × 1014 Hz?
- 2.50 × 1014 m
- 4.00 × 1015 m
- 2.50 × 106 m
- 4.00 × 10-7 m
What is the distance of one light year in kilometers?
- 2.59 × 1010 km
- 1.58 × 1011 km
- 2.63 × 109 km
- 9.46 × 1012 km
How does the illuminance of light change when the distance from the light source is tripled? Cite the relevant equation and explain how it supports your answer.
- if distance is tripled, then the illuminance increases by 19 times.
- if distance is tripled, then the illuminance decreases by 13 times.
- if distance is tripled, then the illuminance decreases by 9 times.
- if distance tripled, then the illuminance increases by 3 times.
A light bulb has an illuminance of 19.9 lx at a distance of 2 m . What is the luminous flux of the bulb?
- 500 lm
- 320 lm
- 250 lm
- 1,000 lm