0
A transmitter radiates 9 kW without modulation and 10.125 kW after modulation. Determine the modulation index.
- A1
- B0.7
- C0.5
- D0.8
Answer not set
Discussion 1
Log in or create a free account to reply and vote.
0
CCommunity
We have, carrier power, $({{\rm{P}}_{\rm{C}}} = 9{\rm{\;kW}})$
Modulated signal power, $({{\rm{P}}_{\rm{T}}} = 10.125{\rm{\;kW}})$
For modulation index, $({{\rm{P}}_{\rm{T}}} = {{\rm{P}}_{\rm{C}}}\left( {1 + \frac{{{{\rm{\mu }}^2}}}{2}} \right))$
$(\begin{array}{l} \Rightarrow {\rm{\mu }} = \sqrt {2\left( {\frac{{{{\rm{P}}_{\rm{T}}}}}{{{{\rm{P}}_{\rm{C}}}}} - 1} \right)} \\ \Rightarrow {\rm{\mu }} = \sqrt {2\left( {\frac{{10.125}}{9} - 1} \right)} \\ \Rightarrow {\rm{\mu }} = 0.5 \end{array})$
Modulated signal power, $({{\rm{P}}_{\rm{T}}} = 10.125{\rm{\;kW}})$
For modulation index, $({{\rm{P}}_{\rm{T}}} = {{\rm{P}}_{\rm{C}}}\left( {1 + \frac{{{{\rm{\mu }}^2}}}{2}} \right))$
$(\begin{array}{l} \Rightarrow {\rm{\mu }} = \sqrt {2\left( {\frac{{{{\rm{P}}_{\rm{T}}}}}{{{{\rm{P}}_{\rm{C}}}}} - 1} \right)} \\ \Rightarrow {\rm{\mu }} = \sqrt {2\left( {\frac{{10.125}}{9} - 1} \right)} \\ \Rightarrow {\rm{\mu }} = 0.5 \end{array})$