Radio waves sent out by a radio stations are reflected by
A). Troposphere
B). Stratosphere
C). Mesosphere
D). Ionosphere
Ionosphere
This is a layer of atmosphere about 60 to 70 km above the earth and extends to about 400km. It contains ionised particles which can reflect radio waves making radio communication round the world possible.
2. In the electrical circuit of a house, the fuse acts as
3. Electron microscope was invented by
4. The frequency of ultrasound wave is typically
5. Refrigeration is a process which
6. Which of the following is an example of simple harmonic motion?
7. An image formed by a concave mirror on a screen is called __________?
8. Necessary element of change in solar energy to electrical energy
9. What is the unit of electric resistance?
10. Which word is related to processing the speed in computers ?