CBSE Class 12 · 2004 · SemiconductorsVery Short Answer

Draw the voltage-current characteristic of a p-n junction diode in forward bias.

Solution

In forward bias the applied voltage opposes the barrier potential.
Until the knee (cut-in) voltage (about

0.3 V

for Ge and

0.7 V

for Si) the current is negligible; beyond it the barrier is largely overcome and the current increases rapidly with voltage.

Small current below the knee voltage, steep rise above it.

CBSE Class 12 Board · 2004 · Subjective