Question
An eclipse of the Sun happens when the Moon comes between the Earth and the Sun.
Which statement is correct?
- Infrared radiation from the Sun disappears before visible light and ultraviolet radiation.
- Ultraviolet radiation from the Sun disappears before visible light and infrared radiation.
- Visible light from the Sun disappears before ultraviolet radiation and infrared radiation.
- Infrared radiation, ultraviolet radiation and visible light from the Sun all disappear at the same moment.
Answer/Explanation
Ans:
D
Question
The diagram shows the electromagnetic spectrum.
A word is missing from the label below the spectrum.
Which word is missing?
A amplitude
B frequency
C speed
D wavelength
Answer/Explanation
Ans:D
Question
An intruder alarm sensor detects that a person is warmer than his surroundings.
Which type of electromagnetic wave does the sensor detect?
-
infrared
-
radio
-
ultraviolet
-
visible light
Answer/Explanation
Ans: AQuestion
Which row gives the approximate speeds at which ultraviolet waves travel in air and in a vacuum?
Answer/Explanation
Ans: D
Question
Here are three statements about the speed of electromagnetic waves.
The speed of an electromagnetic wave in a vacuum is 340 m / s.
The speed of an electromagnetic wave in a vacuum is 3.0 108 m / s.
The speed of an electromagnetic wave in a vacuum is approximately the same as in air.
Which statements are correct?
A 1 and 3 B 1 only C 2 and 3 D 2 only
Answer/Explanation
Ans: C