Question

Carson’s rule for estimating the bandwidth (B) of an FM signal is:

• A. $B = 2f_m$
• B. $B = 2\Delta f$
• C. $B = 2(\Delta f + f_m)$
• D. $B = 2(\Delta f \times f_m)$

Hint:

FM bandwidth ≈ $2(\Delta f + f_m)$.

Answer 1

The Correct Option is C

Concept: Carson’s Rule gives approximate bandwidth of FM signal: \[ B = 2(\Delta f + f_m) \] where:
• $\Delta f$ = frequency deviation
• $f_m$ = modulating frequency

Step 1: Interpretation Bandwidth includes:
• Deviation spread
• Modulating frequency components

Step 2: Apply formula \[ B = 2(\Delta f + f_m) \] \[ \therefore \text{Correct answer is (C)} \]