physics : class12 Medium-Wave Radio : Radio Waves : Electromagnetic Waves MCQ Questions and Answers
Practice important
Medium-Wave Radio
MCQ questions and answers.
Page 1
of
1
|
10
MCQ Questions
1. Medium-wave radio broadcasting commonly uses which type of modulation?
A.
Amplitude modulation
B.
Ultraviolet modulation
C.
X-ray modulation
D.
Gamma-ray modulation
Correct Answer:
Amplitude modulation
Explanation:
Medium-wave broadcasting is traditionally associated with amplitude modulation, in which the amplitude of a carrier wave is varied according to the audio signal.
2. Which frequency range is generally associated with medium-wave AM broadcasting?
A.
530 kHz to 1700 kHz
B.
3 Hz to 30 Hz
C.
30 MHz to 300 MHz
D.
3 GHz to 30 GHz
Correct Answer:
530 kHz to 1700 kHz
Explanation:
Medium-wave AM broadcast stations commonly operate in the frequency range of approximately 530 kHz to 1700 kHz.
3. What is the approximate wavelength of a medium-wave radio signal with a frequency of 1 MHz?
A.
3 m
B.
30 m
C.
300 m
D.
3000 m
Correct Answer:
300 m
Explanation:
Using the relation wavelength = speed of light divided by frequency, the wavelength is 3 × 10^8 m/s divided by 1 × 10^6 Hz, which equals about 300 m.
4. During daytime, medium-wave radio signals mainly reach nearby receivers by which mode of propagation?
A.
Ground-wave propagation
B.
X-ray propagation
C.
Ultraviolet propagation
D.
Gamma-ray propagation
Correct Answer:
Ground-wave propagation
Explanation:
During the day, medium-wave signals commonly travel along the Earth's surface as ground waves, allowing reception over moderate distances.
5. Why can medium-wave radio stations often be heard over greater distances at night?
A.
The ionosphere can reflect the waves back toward Earth
B.
The waves change into sound in space
C.
The waves stop carrying information
D.
The frequency becomes zero at night
Correct Answer:
The ionosphere can reflect the waves back toward Earth
Explanation:
At night, reduced ionization in the lower ionosphere can allow medium-wave signals to be reflected or refracted back toward Earth, increasing their range.
6. Which device is commonly used to select a particular medium-wave radio station in an AM receiver?
A.
Tuning circuit
B.
Thermometer
C.
Barometer
D.
Photographic lens
Correct Answer:
Tuning circuit
Explanation:
A tuning circuit selects the desired station by resonating at, or near, its carrier frequency in the medium-wave band.
7. If the frequency of a medium-wave radio signal increases, what happens to its wavelength?
A.
It increases
B.
It decreases
C.
It remains infinite
D.
It becomes zero immediately
Correct Answer:
It decreases
Explanation:
For electromagnetic waves traveling at approximately constant speed, wavelength and frequency are inversely related by c = fλ.
8. Medium-wave radio signals are electromagnetic waves, so they can travel through which medium?
A.
Vacuum
B.
Only liquid water
C.
Only metals
D.
Only glass
Correct Answer:
Vacuum
Explanation:
Electromagnetic waves do not require a material medium and can propagate through a vacuum, although medium-wave signals are also transmitted through the atmosphere.
9. What is the main purpose of the carrier wave in medium-wave radio broadcasting?
A.
To carry the audio information over a distance
B.
To produce visible light
C.
To measure air pressure
D.
To heat the receiver antenna
Correct Answer:
To carry the audio information over a distance
Explanation:
In medium-wave AM broadcasting, the audio signal is imposed on a higher-frequency carrier wave so that it can be transmitted and received efficiently.
10. Which type of antenna is commonly used for receiving medium-wave AM signals?
A.
Ferrite-rod loop antenna
B.
Parabolic radio telescope only
C.
Laser cavity
D.
Microscope objective
Correct Answer:
Ferrite-rod loop antenna
Explanation:
Portable and household AM receivers commonly use a ferrite-rod loop antenna, which is suitable for receiving medium-wave radio signals.
Short Questions and Answers
Practice short questions and answers related to
Medium-Wave Radio
.
Short questions are currently unavailable for this page.