This question was previously asked in

ESE Electrical 2014 Paper 2: Official Paper

Option 3 : 0.6

CT 3: Building Materials

2962

10 Questions
20 Marks
12 Mins

__Concept:__

For an Amplitude modulated wave with carrier amplitude A_{C}, the maximum and minimum amplitude is given by:

A_{max} = Ac(1 + μ)

A_{min} = Ac(1 - μ)

\(\frac{{{A_{max}}}}{{{A_{min}}}} = \frac{{1 + μ}}{{1 - μ}}\)

The above can be written as:

\(μ = \frac{{{A_{max}} - {A_{min}}}}{{{A_{max}} + {A_{min}}}}\)

__Calculation__:

Given Amax = 160 V and Amin = 40 V

The modulation index will be:

\(μ = \frac{{{160} - 40}}{{160 + 40}}=\frac{120}{200}\)

**μ = 0.6**