Electron devices

In a PN junction with no external voltage the electric field between acceptor and donor ion is called a

• peak

• barrier

• threshold

• path

The capacitance of reverse biased pn junction

• Increases as reverse bias increased

• Decreases as reverse bias decreased

• increases as reverse bias decreased

• is significantly low

For a pn junction diode,the current in reverse bias may be

• Few millamperes

• between 0.2A and 15A

• few amperes

• few micro or nano amperes

In a PN junction when the applied voltage overcomes the _____potential, the diode current is large which

is known as______

• Depletion, negative bias

• reverse , reverse bias

• resistance ,reverse bias

• barrier , forward bias

The main reason why electrons can tunnel through a PN junction is that

• barrier pontential is very low

• they have high energy

• impurity level is low

• Depletion layer is extremely thin

A reverse biased PN junction has

• net electron current

• net hole current

• very narrow depletion layer

• almost zero current

Depletion layer of PN junction is one that is depleted of

• immobile charge

• mobile charge

• atom

• none

Barrier potential of PN junction is caused by

• Flow of drift current

• diffusion of majority carriers across the junction

• migration of minority carriers across the junction

• thermally generated electron and holes

A transistor has how many doped regions

• 1

• 2

• 3

• 4

Emitter diode is usually

• Forward bias

• Reverse bias

• Non conducting

• operating in breakdown region