เสียงที่ใช้ร่วมกัน

for instance, in this circuit, the voltmeter reads the line integral of the electric field through the meter. Since there’s no magnetic flux, then the curl of E is equal to zero and the electric field is conservative. So the line integral of E is independent of the path and the potential is defined at point a and b and the voltage is the difference between the Va and Vb.