How does the voltage tester pen judge the circuit breakage
As shown in the figure below, after closing the key S, it is found that the light L is not on, and the fuse is not blown. Use a test pen to test the two wires C and D of the lamp head, both of which can make the neon tube of the test pen glow, and then use the test pen to test the live wire A and the neutral wire B. B does not emit light.
Where is the fault point? ( )
Analysis of Problems in Judging Circuit Breaks by Electric Test Pen
A. Short circuit between live wire and neutral wire
B. Lamp L is short-circuited
C. There is an open circuit somewhere in the AC section of the wire
D. There is an open circuit somewhere in the BD section of the wire
