Correct Answer - Option 3 : 24 kHz
Concept:
According to Carson rule signal, BW is given as:
B.W = (β + 1) 2fm
\(\becauseβ=\frac{Δf}{f_m} \)
B.W. = 2[Δf + fm]
If multiple frequencies are available in modulating signal then,
B.W. = 2(β + 1) fmax
Calculation:
Given:
Δf = 10 kHz
fm = 2 kHz
B.W. = 2[Δf + fm]
B.W. = 2(10 + 2)
BW = 24 kHz
Hence option (3) is the correct answer.