Modulation index of wideband FM systemA. >1B. < 1C. = 1D. NoneSelect one:a. Db. Bc. Ad. C

Step 1: Break Down the Problem

You need to determine the modulation index of a wideband Frequency Modulation (FM) system and select the correct answer from the options provided.

Step 2: Relevant Concepts

The modulation index (β) for FM is defined as: $\beta = \frac{\Delta f}{f_m}$ where:

• $\Delta f$ is the frequency deviation,
• $f_m$ is the maximum frequency of the modulating signal.

In wideband FM systems, the modulation index is usually greater than 1.

Step 3: Analysis and Detail

For wideband FM:

• The frequency deviation is significant relative to the highest frequency of the modulating signal.
• Therefore, it is common for the modulation index (β) to be greater than 1.

This implies that for wideband FM, the modulation index does not equal 1 or is less than 1.

Step 4: Verify and Summarize

From FM theory, we understand that for a system to be considered wideband, the modulation index must exceed 1.

Final Answer

The correct choice is: A. >1.