Question

An antenna behaves as a resonant circuit only when the length is

• A. equal to $\lambda /4$
• B. equal to $\lambda /2$
• C. equal to the integral multiples of $\lambda /2$
• D. equal to $3\lambda /4$

Answer 1

The correct option is C equal to the integral multiples of $\lambda /2$

Condition for resonance: The length of the antenna should compose of $n$ nodes and $n+1$ antinodes.
Hence, $l=\frac{n\lambda }{2}$