A carrier wave of peak voltage 14 V is used for transmitting a message signal. The peak voltage of modulating signal given to achieve a modulation index of 80 % will be:

Question

A carrier wave of peak voltage 14 V is used for transmitting a message signal. The peak voltage of modulating signal given to achieve a modulation index of 80 % will be: (A) 7 V (B) 28 V (C) 11.2 V (D) 22.4 V

Tardigrade Admin · Accepted Answer

Amplitude of carrier wave is A c =14 V Index is μ=80 %=0.80 Amplitude of modulating signal is given by μ=(A m /A c ) ⇒ A m =μ A c ⇒ A m =0.8 × 14=11.2 V

Q. A carrier wave of peak voltage $14 V$ is used for transmitting a message signal. The peak voltage of modulating signal given to achieve a modulation index of $80%$ will be:

$7 V$

$28 V$

$11.2 V$

$22.4 V$

Amplitude of carrier wave is $A_{c} = 14 V$
Index is $μ = 80% = 0.80$
Amplitude of modulating signal is given by
$μ = \frac{A _{m}}{A _{c}}$
$\Rightarrow A_{m} = μ A_{c}$
$\Rightarrow A_{m} = 0.8 \times 14 = 11.2 V$

Q. A carrier wave of peak voltage 14V is used for transmitting a message signal. The peak voltage of modulating signal given to achieve a modulation index of 80% will be:

7V

28V

11.2V

22.4V