Question

In FM, when frequency deviation is doubled, then

• A. modulation is halved.
• B. carrier swing is halved.
• C. modulation is doubled.
• D. modulation index is decreased.

Answer 1

The correct option is C modulation is doubled.

$m=\frac{{\left(\Delta f\right)}_{actual}}{{\left(\Delta f\right)}_{max}}\times 100⟹m\propto {\left(\Delta f\right)}_{actual}$

So, if frequency deviation is doubled then modulation is doubled.