In a transistor
Transistors are essentially
In the symbol of a transistor , the arrow head points in the direction of flow of
The mobility of conduction electrons is greater than that of holes, since electrons
If the conductivity of a semiconductor is only due to breakup of the covalent bonds due to thermal excitation, then the semiconductor is called
In an intrinsic semiconductor
A piece of copper and another of germanium are cooled from room temperature to 80 K. The resistance of
Application of a forward bias to a p–n junction
Number of donors is more because electrons from– ve terminal of the cell pushes (enters) the n-side and decreases the number of uncompensated pentavalent ion due to which potential barrier is reduced. The neutralised pentavalent atom are again in position to donate electrons
In semiconductors, at room temperature
In semiconductros, the conduction is empty and the valence band is completely filled at 0K. No electron from valence band can cross overto conduction band at 0K. But at room temperature some electrons in the valence band jump over to the conduction band dueto the small for bidden gap, i.e. 1 eV.
Reverse bias applied to a junction diode
In reverse biasing, the conduction across the p-n junction does not take place due to majority carriers but takes place due to minority carriers if the voltage of external battery is large. The size of the depletion region increases there by increasing the potential barrier.