Questenaتمرینی که نشان می‌دهد بعد چه چیزی را مرور کنید
سؤال 359

What must be done to prevent standing waves on a feed line connected to an antenna?

  1. The antenna feed point must be at DC ground potential
  2. The feed line must be an odd number of electrical quarter wavelengths long
  3. The feed line must be an even number of physical half wavelengths long
  4. The antenna feed point impedance must be matched to the characteristic impedance of the feed lineپاسخ درست

توضیح

Standing waves exist only where a reflected wave is present, and no reflection occurs when the load equals the line's characteristic impedance. Choosing a particular line length does not remove the reflection; it only moves the standing wave pattern along the line.

ادامهٔ این آزمون

شروع تمرین
سؤال 359: What must be done to prevent standing waves on a feed line… · FCC General Class (Element 3) · Questena