Home/
Competitive Exams/
JEE Main & Advanced/
Physics/
Semiconductors/
Question 20229
JEE Physics · Medium

Semiconductors: Avalanche Breakdown MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

Timer-based practiceDetailed answer reviewMobile-friendly flow
Avalanche BreakdownMediumQuestion 20229

Question

Avalanche breakdown in a reverse-biased diode occurs due to:
  1. A
    Quantum tunneling of carriers across the junction
  2. B
    High-velocity carriers ionising more atoms by impact (impact ionisation), creating an avalanche of carriers
    Correct
  3. C
    Thermal runaway
  4. D
    Zener effect only

Correct answer

High-velocity carriers ionising more atoms by impact (impact ionisation), creating an avalanche of carriers

Explanation

At high reverse voltage, thermally generated minority carriers gain enough energy to ionise silicon atoms → more electron-hole pairs → these also ionise → avalanche multiplication → current rises sharply. Zener breakdown (~≤5 V) is quantum tunneling; avalanche (>5 V) is impact ionisation.

Review Semiconductors notesStart timed chapter practice