Q 12-08-120JEE MainJEE Main 2022 (24 Jun, Shift 1)Easy
A baseband signal of $3.5\ \text{MHz}$ frequency is modulated with a carrier signal of $3.5\ \text{GHz}$ frequency using amplitude modulation method. What should be the minimum size of antenna required to transmit the modulated signal?
Answer: (C) $21.4\ \text{mm}$
The transmitted wave is at the carrier frequency: $\lambda = \dfrac{3\times10^8}{3.5\times10^9} = 85.7\ \text{mm}$.
Minimum antenna length $= \dfrac{\lambda}{4} \approx 21.4\ \text{mm}$.
Solution by Sreeraj P, M.Sc Physics