Calculation of Modulation index in FM signal
A 100MHz carrier is frequency modulated by 10 KHz wave. For a frequency deviation of 50 KHz, calculate the modulation index of the FM signal.
Options:
a) 100
b) 50
c) 70
d) 90
Correct Answer: b) 50
Explanation:
Carrier frequency fc= 100MHz
Modulating frequency fm= 10 KHz
Frequency deviation Δf = 500 KHz
Modulation index of FM signal is given by
mf = Δf/fm
= 500*103/ 10*103
= 50
Discussion
- RE: Calculation of Modulation index in FM signal -babur (01/19/19)
- i think by mistake anwer given is wrong , actual freq deviatiion is 50 KHz
mod index= freq deviaition / mod freq
freq deviation is 50 KHz, mod freq is 10 KHz
mod index = 50 KHz/ 10 KHz
mod index = 5 ( in my last post i mentioned KHz which is wrong)
- RE: Calculation of Modulation index in FM signal -babur (01/19/19)
- i think answer given is wrong by mistake and fol is probably the right soulution;
freq deviation is given 50 khz,
mod index= freq deviation / mod freq
= 50/10 khz
5 khz is answer - RE: Calculation of Modulation index in FM signal -MUHAMMAD HAMID (01/20/18)
- sir here in statement of MCQ f.d=5khz and calculation the f.d=5khz so this in correct.plz correct this one
