If the frequency of an EM wave is 10 MHz, then its wavelength is:
1. 30 m
2. 300 m
3. 3 m
4. none of the above
1. | b>a>c | 2. | a>b>c |
3. | c>b>a | 4. | a>c>b |
The biological importance of the ozone layer is:
1. | it stops ultraviolet rays. |
2. | ozone layer reduces the greenhouse effect. |
3. | ozone layer reflects radio waves. |
4. | ozone layer controls O2/H2 ratio in the atmosphere. |
Which of the following has the minimum wavelength?
1. X-rays
2. Ultraviolet rays
3. γ-rays
4. Cosmic rays
What is the cause of “Greenhouse effect”?
1. Infra-red rays
2. Ultraviolet rays
3. X-rays
4. Radio waves
The velocity of electromagnetic waves is parallel to:
1. →B×→E
2. →E×→B
3. →E
4. →B
If λv,λx, and λm represent the wavelengths of visible light, x-rays and microwaves respectively, then:
1. λm>λx>λv
2. λv>λm>λx
3. λv>λx>λm
4. λm>λv>λx