Zaymiey

⚛️ Physics  ·  Semiconductor Electronics  ·  NEET & JEE

A Zener diode of breakdown voltage 6 V is used in a regulator with a 9 V supply and a 300 Ω series resistor. The current through the series resistor is:

Answer: 10 mA.

  • A 10 mA
  • B 5 mA
  • C 20 mA
  • D 30 mA

Correct answer: A. 10 mA

Explanation: Voltage across the series resistor = 9 − 6 = 3 V, so current = 3 V / 300 Ω = 0.01 A = 10 mA.

Conductorconduction bandvalence bandbands overlapSemiconductorconduction bandvalence bandsmall gap (~1 eV)Insulatorconduction bandvalence bandlarge gap(> 3 eV)

Conductors have overlapping bands, semiconductors have a small energy gap that can be bridged by heat or doping, and insulators have a large gap that blocks conduction.

Concept context

Band theory, p-n junction, diodes, transistors, logic gates, and integrated circuits.

Read the full Semiconductor Electronics notes →