1.suppose you wish to transmit an electro signal in the audio frequency range over a long distance directly .write briefly the three important factors which prevent you from doing so and explain how you overcome these factors?
2.for an amplitudec modulated wave the maximum amplitude is found to be 10 v while the minimum amplitude is 2v .determine the value of modulation index u
what would be the value of u if the minimum amplitude is zero volt?why is u generally kept less than !?

Asked by mahamood.iphone | 23rd Dec, 2015, 07:37: AM

Expert Answer:

Maximum amplitude, Emax = 10 V
Minimum amplitude, Emin = 2 V
begin mathsize 14px style straight mu equals fraction numerator Emax minus Emin over denominator Emax plus Emin end fraction equals fraction numerator 10 minus 2 over denominator 10 plus 2 end fraction equals 8 over 12 equals 2 over 3 end style
When the minimum amplitude is zero volt i.e., Emin =0, then μ = 1 irrespective of the value of Emax.
Modulation index is kept less than 1 to avoid distortions.
Note: Kindly ask the other question as a separate query.

Answered by Faiza Lambe | 23rd Dec, 2015, 09:24: AM