Question

1. What does "in phase" mean with respect to the voltages and current in an AC circuit?

2. How does a doped semiconductor differ from a non-doped semiconductor?

Answer 1

Answer. 1: Phase means with respect to the voltages and current in an AC circuit is defined as the fraction of the time period that has elapsed , since the e.m.f (or current) last passed its zero value in the positive direction.

Answer. 2: In Doped semiconductor. It have better conductivity. The energy gap is higher between conduction and valence band.

Fermi level varies according to the type of semiconductor (doped). The conduction depends on the concentration of doped impurity and temperature. It have p-type and n-type semiconductor. Ex GaAs, Gap etc.

In non-doped semiconductor, there is no impurity concentration is present in it. It have less movable electrons , so its exhibits poor conductivity. Band gap between conduction and valence bond is small.Fermi level is present in the middle of forbidden energy gap. Its conduction relies on the temperature . Ex Si, Ge etc.

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