NEW
Font size
WorksheetsElectron devices
Total questions: 25
Worksheet time: 19mins
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
most of the electrons in the base of an npn transistor flow
out of the base lead
into the collector
into the emitter
into the base supply
The current gain of a transistor ratio of the
collector current to emitter current
collector current to base current
base to collector current
emitter to collector current
The fact that only a few holes are in base region means that base is
lightly doped
heavily doped
undoped
none
If the current gain is 200 and the collector current is 100mA the base current is
0.5mA
2mA
2A
20A
Transistor acts like diode and a
voltage source
current source
power supply
resistance
In a active region collector current is not changed significantly by
supply voltage
base current
current gain
collector resistance
A current ratio of IC/IE is usually less than one and is called
beta
theta
alpha
omega
In transistor collector current is controlled by
collector voltage
base current
collector resistance
all of the above
when a silicon transistor is properly biased what is VBE for a C-E configuration
voltage divider bias
0.3v
0.7v
0.0v
In CB configuration of transistor the input impedence is
high
medium
low
none
A JFET has 3 terminals , namely
cathode,anode,grid
emitter,base,collector
source,gate,drain
none
The gate of a JFET is ______biased
reverse
forward
reverse as well as forward
none
A JFET has _____power gain
small
very high
very small
none
When drain voltage equals the pinch off voltage then drain current ______with the increase in
drain voltage
decreases
increases
remains constant
none
Saturation region of a JFET is also known as _______region
Pinch off
analog
source
ohmic
