What impedance does a 1/4-wavelength transmission line present to an RF generator when the line is open at the far end?
The same as the characteristic impedance of the line
The same as the input impedance to the generator
Very high impedance
Very low impedance✓Correct answer
Explanation
A quarter-wave section inverts its termination, so an open circuit at the far end appears as a short circuit at the input. The generator therefore sees an impedance close to zero, the section behaving like a series-resonant circuit.