Chapter-3 Bipolar Junction Transistors

Example-3.1(a) Page Number-136

In [3]:
Ie=3          #in mA(emitter current)
Vcb=10        #in volts(collector-base voltage)
#from the characterstics given in the question
#looking at the intersection of line Vcb=10V and Ie=3mA,
Ic=3          #in mA(collector current)
print "Collector current(Ic)=",Ic,"mA"

Collector current(Ic)= 3 mA

Example-3.1(b) Page Number-136

In [6]:
Ie=3          #in mA(emitter current)
Vcb=2        #in volts(collector-base voltage)
#from the characterstics given in the question
#looking at the intersection of line Vcb=2V and Ie=3mA,
Ic=3          #in mA(collector current)
print "Collector current(Ic)=",Ic,"mA"
print "Change in Ic is negligible"

Collector current(Ic)= 3 mA
Change in Ic is negligible

Example-3.1(c) Page Number-136

In [7]:
Ic=4         #in mA(collector current)
Vcb=20       #in volts(collector-base voltage)
#from the characterstics given in the question
#from the 2nd charcterstics,
Ie=Ic
#looking at the intersection of line Vcb=20V and Ie=Ic=4mA,
Vbe=0.74     #in volts(base-emitter voltage)
print "Vbe=",Vbe,"V"

Vbe= 0.74 V

Example-3.1(d) Page Number-136

In [9]:
Ic=4         #in mA(collector current)
Vcb=20       #in volts(collector-base voltage)
#from the characterstics given in the question
#from the 1st charcterstics,
Ie=Ic
#from the 2nd charcterstics,Vbe is always 0.7V for any Ie
Vbe=0.7      #in volts(base-emitter voltage)
print "Vbe=",Vbe,"V"

Vbe= 0.7 V

Example-3.2(a) Page Number-141

In [11]:
Ib=30            #in microA (base current)
Vce=10           #in volts(collector-emitter voltage)
#from the characterstics given in the question,
#looking at the intersection of line Vce=10V and Ib=30microA,
Ic=3.4           #in mA(collector current)
print "collector current(Ic)=",Ic,"mA"

collector current(Ic)= 3.4 mA

Example-3.2(b) Page Number-141

In [12]:
Vce=15           #in volts(collector-emitter voltage)
Vbe=0.7           #in volts(collector-emitter voltage)
#from the characterstics of Vbe vs Ib given in the question,
#looking at the intersection of line Vce=15V and Vbe=0.7V,

Ib=20           #in microA(base current)

#from the characterstics of Vce vs Ic given in the question,
#looking at the intersection of line Vce=15V and Ib=0.7 microA,

Ic=2.5          #in mA(collector current)
print "collector current(Ic)=",Ic,"mA"

collector current(Ic)= 2.5 mA