Question

Select True or False for the following statements about electromagnetic waves.

1. Gamma rays can be produced in transitions of an atomic nucleus from one state to another.
2. The Earth's atmosphere is quite transparent to infrared radiation.
3.Radio waves have wavelengths longer than 1 m.
4. Radio waves travel in vacuum at a lower speed than the visible light.
5. X-rays are produced by a glowing light bulb.
6. The sun's radiation is most intense in the visible region.
7. A vertical automobile antenna is sensitive to electric fields polarized horizontally.

Answer 1

1) True: Gamma rays are high energy photons which cannot be produced when electrons make transitions from one state to another, but can easily be producedwhen the nuclei changes states due to the much higher energies in the nucleus.

2) False: The earth's atmosphere is mostly opaque to infrared radiation. Very little makes it to the earth's surface.

3) True: While there is no precise standard for where radio waves begin, 1m in wavelength is in the correct area for the transition between microwave andradio waves

4) False: Radio waves and visible light are both types of electromagnetic radiation and in a vacuum will travel at exactly the same speed, namely the speedof light in a vacuum which is precisely 299 792 458 m / s

5) True: A hot body emits a continuous spectrum of different types of radiation - known as blackbody radiation - and the hotter it is the more of higherenergies are produced. At the temperature of a light bulb filament (~4000 K) most of the light is visible or infrared, but a small amount of x rays arestill produced

6) True: The sun emits primarily in the visible portion of the spectrum but is hot enough that it does emit significantly in the others as well

7) False: The antannae is vertically oriented and so is most sensitive to electric fields polarized vertically

Answer 2

1 true
2 true
3 true
4 false
5 false
6 false
7 true

Answer 3

1) True
2) True
3) True
4) False
5) False
6) False
7) False