# Chapter 11 More Amplifier Theory¶

## Example 11.1 Page No 274¶

In [1]:
# given data
r_F= 220##  Ω
r_E= 4.7##in Ω
# The closed loop voltage gain
A_CL= r_F/r_E+1#
print "The closed loop voltage gain = %.2f"%A_CL

The closed loop voltage gain = 47.81


## Example 11.2 Page No 287¶

In [3]:
# given data
h_ie= 3.5*10**3##in Ω
h_fe= 120.0#
h_re= 1.3*10**-4#
h_oe= 8.5*10**-6##  S
bita= h_fe## unit less
# The value of alpha
alpha= h_fe/(h_fe+1)#
print "The value of alpha = %.2f"%alpha
# The value of r'e
r_desh_e= h_ie/h_fe##  Ω
r_desh_c= h_fe/h_oe##  Ω
print "The value of r''e = %.2f Ω"%r_desh_e
# The value of r'c
r_desh_c= r_desh_c*10**-6##  Mohm
print "The value of r''c = %.2f MΩ"%r_desh_c

The value of alpha = 0.99
The value of r''e = 29.17 Ω
The value of r''c = 14.12 MΩ


## Example 11.3 Page No 288¶

In [4]:
# given data
h_rb= 1.75*10**-4#
h_ob= 10**-6##  S
r_desh_b= h_rb/h_ob##  Ω
print "The value of r''b = %.2f Ω"%r_desh_b

The value of r''b = 175.00 Ω


## Example 11.4 Page No 289¶

In [6]:
# given data
h_fe= 120## unit less
h_ie= 3.5*10**3##in Ω
r_L= 2*10**3##  Ω
h_oe= 8.5*10**-6##  S
h_re= 1.3*10**-4## unit less
# The voltage gain
A= h_fe*r_L/(h_ie*(1+h_oe*r_L)-h_re*h_fe*r_L)
print "The voltage gain = %.2f"%A

The voltage gain = 68.02