# A 100 V carrier wave is made to vary between 160 V and 40 V by a modulating signal . What is the modulation index ?Option 1) 0.4Option 2) 0.5Option 3) 0.6Option 4) 0.3

Modulation Index -

The ratio of change of amplitude of carrier wave to the amplitude of original carrier wave.

- wherein

$m_{a}= \frac{E_{m}}{E_{c}}$

$A_{c}=100V$

$A_{c}+A_{m}=160V=A\, \, max\, \, \, \, \, \, \left ( 1 \right )$

$A_{c}-A_{m}=40=A\, min\, \, \, \, \, \, \left ( 2 \right )$

From (1) & (2)

$A_{c}=100V$  &   $A_{m}=60m$

So  $\mu =\frac{A_{m}}{A_{c}}=0.6$

Option 1)

0.4

Option 2)

0.5

Option 3)

0.6

Option 4)

0.3

Exams
Articles
Questions