Radio waves are the waves having the longest wavelength in the electromagnetic spectrum. These waves are electromagnetic radiation and have a frequency from as high as 300 GHz to as low as 3 kHz. At 300 GHz, the wavelength is 1 mm and at 3 kHz it is 100 km. They travel at the speed of light just like all other electromagnetic waves do. Lightning or astronomical objects make all the waves that have naturally occurred. Artificially formed radio waves are used in radio communication, radar, computer networks, broadcasting, different navigation systems and different applications.
Q1: Mathematical prediction of radio waves was done by
- Einstein
- Hertz
- Faraday
- Maxwell
Answer: (d) Maxwell
Q2: The electric field and magnetic field of a radio wave are
- Perpendicular to each other
- Perpendicular to the direction of propagation
- Both a and b
- None of the above
Answer: (c) Both a and b
Q3: The speed of radio wave in free space is
- 3 x 106 metres/second
- 3 x 108 metres/second
- 3 x 106 miles/second
- 3 x 108 miles/second
Answer: (b) 3 x 108 metres/second
Q4: Radio waves would strongly reflect off
- A flat insulating surface of the right size
- A flat metallic surface of the right size
- A flat dielectric surface of the right size
- A flat body of water
Answer:(b) A flat metallic surface of the right size
Q5: Radio waves sometimes bend around the corners due to
- Reflection
- Diffusion
- Refraction
- Diffraction
Answer: (d) Diffraction
Q6: Which of the following is the phenomenon caused when Radio waves travel in two or more paths during propagation and produce slowly-changing phase differences between signals?
- Absorption
- Fading
- Baffling
- skip
Answer: (b) fading
Q7: High-frequency long-distance propagation mostly depends on
- Ionospheric reflection
- Tropospheric reflection
- Ground reflection
- Inverted reflection
Answer: (a) Ionospheric reflection
Q8: What is the distance from the far end of the ground wave to the nearest point where the sky wave returns to earth called?
- Angle of radiation
- maximum usable frequency
- Skip distance
- Skip zone
Answer: (d) Skip zone
Q9: Which of the following are electromagnetic
- Radio waves
- Light
- Gamma waves
- All the above
Answer: (d) All the above
Q10: The radio waves were demonstrated experimentally by
- Hertz
- Maxwell
- Marconi
- Armstrong
Answer: (a) Hertz
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Daily Quiz #66 | Class 11-12 | Physics | NEET
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