Multiple Choice QuestionsWhich of the following statement is wrong ?
Ground wave propagation can be sustained at frequencies 500 kHz to 1500 kHz.
Statellite communication is useful for the frequencies above 30 MHz.
Sky wave propagation is useful in the range of 30 to 40 MHz.
Sky wave propagation takes place through tropospheric space.
A signal wave of frequency 12 kHZ is modulated with a carrier wave of frequency 2.51 MHz. The upper and lower side band frequencies are respectively
2512 kHz and 2508 kHz
2522 kHz and 2488 kHz
2502 kHz and 2498 kHz
2522 kHz and 2498 kHz
D.
2522 kHz and 2498 kHz
Upper side band (USB) frequency = fc + fm
= (2.51) MHz + (12) kHz
= (2510 + 12) kHz
= 2522 kHz
Lower side band (LSB) frequency = fc − fm
= (2.51) MHz − (12) kHz
= (2510 − 12) kHz
= 2498 kHz
Switch
