Why does the current stop flowing when connected in parallel?

Question

Electronics

There is light bulb 5, why, if current flows simultaneously through 10 and 12 wires, does it go out?
And why is there a diode after it?

Answer 1

You have circuits:
10 - indicator - diode - resistor - 1 (common)
12 - resistor - 1 (common)
If you apply voltage to pin 12, then the voltage will drop on the resistor, which locks the diode and it does not conduct current, or conducts current , but it is not enough for the indicator to glow.