Question

What is the radiation resistance of an antenna if it radiates 1kW and current in it is Irms=10A?

(a) 0.1Ω

(b) 1Ω

(c) 10Ω

(d) 100Ω

I have been asked this question during a job interview.

The origin of the question is Radiation Resistance topic in chapter Antenna Parameters of Antennas

Answer 1

The correct choice is (c) 10Ω

For explanation: Power radiated Prad=Irms^2 Rrad

⇨ Rrad=\(\frac{P_{rad}}{I_{rms}^2} = \frac{1000}{10×10}=10\Omega\)