E6A03

Why does a PN-junction diode not conduct current when reverse biased?

1. AOnly P-type semiconductor material can conduct current
2. BOnly N-type semiconductor material can conduct current
3. CHoles in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region
4. DExcess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator

Pick an answer to check it.