Questenaتدريب يوضح لك ما ينبغي مراجعته لاحقًا
السؤال 167

Why do voltmeters have high input impedance?

  1. It improves the frequency response
  2. It allows for higher voltages to be safely measured
  3. It improves the resolution of the readings
  4. It decreases the loading on circuits being measuredالإجابة الصحيحة

الشرح

A voltmeter is connected in parallel with the point being measured, so it forms a divider with the source impedance and draws current from the circuit. Making its input impedance high keeps that current negligible so the reading reflects the voltage that was there before the meter was attached.

تابع هذا الاختبار

بدء التدريب
السؤال 167: Why do voltmeters have high input impedance? · FCC General Class (Element 3) · Questena