Chapter 2 The fundamentals of Electronics: A Review

Example 2.1 Page no 31

In [2]:
#given
vout=750*10**-3
vin = 30*10**-6

#calculation
gain=vout/vin

#Result
print"The Voltage gain of the amplifier is ",gain

The Voltage gain of the amplifier is  25000.0

Example 2.2 Page no 31

In [3]:
#given
pout=6
power_gain=80.0

#calculation
pin=pout/power_gain

#Result
print"The input power of the signal is ",pin*1000,"mW"

The input power of the sigmal is  75.0 mW

Example 2.3 Page no 32

In [4]:
#given
A1=5;
A2=2;
A3=17;
total_gain=A1*A2*A3;
pin= 40*10**-3;

#calculation
pout=total_gain*pin;

#Result
print"The output power is",pout,"watts"

The output power is 6.8 watts

Example 2.4 Page no 32

In [7]:
#given
pin=25.0*10**-6;
pout=1.5*10**-3;
A1=3.0;

#Calculation
total_gain=pout/pin;
print"Total gain is",total_gain
A2=total_gain/A1

#Result
print"The gain of second stage is ",A2

Total gain is 60.0
The gain of second stage is  20.0

Example 2.5 Page no 34

In [7]:
#given
R1=10.0*10**3;
R2=470.0;

#Calculation
attenuation=R2/(R2+R1)
A2=1/attenuation

#Result
print"(a) The attenuation (A1) is",round(attenuation,3)
print"(b) The attenuation (A2) is",round(A2,1)

(a) The attenuation (A1) is 0.045
(b) The attenuation (A2) is 22.3

Example 2.6 Page no 35

In [6]:
#given
Vin=20.0*10**-6;
Vout=100*10**-3;
A1=45000.0                                #A1 isAmplifier gain

#calculation
AT=Vout/Vin                                #AT is Total gain
A2=AT/A1                                   #A2 is attenuation factor

#Result
print"Total gain is",AT
print"The atenuation factor needed to to keep the output voltage from exceeding 100 mv is ",round(A2,4)

Total gain is 5000.0
The atenuation factor needed to to keep the output voltage from exceeding 100 mv is  0.1111

Example 2.7 Page no 36

In [11]:
#given
Vin=3.0*10**-3
Vout=5
Pin=50.0*10**-3                                     
Pout=2*10**-3                                     

#calculation
import math
gain_dB= 20*log10 (Vout/Vin)
gain_db=10*log10 (Pout/Pin)

#Result
print"(a) The gain of amplifier in dB is ",round(gain_dB,1)
print"(b) The gain in dB is ",round(gain_db,2)

(a) The gain of amplifier in dB is  64.4
(b) The gain in dB is  -13.98

Example 2.8 Page no 38

In [19]:
#given
gain_dB = 40
pout_W= 100

#calculation
pin_W = pout_W/10.0**4

#Result
print"The input power is ",pin_W,"Watt"
 

The input power is  0.01 Watt

Example 2.9 Page no 38

In [21]:
#given

gain_db = 60
vin = 50*10**-6

#calculation
vout = 10**(60/20.0)*vin

#Result
print"The output voltage is ",vout,"volt"

The output voltage is  0.05 volt

Example 2.10 Page no 39

In [13]:
#given

vin=90*10**-3
R1= 10.0*10**3
vout=7.8
Rout=8.0

#calculation
pin= vin**2/R1
pout=vout**2/Rout

import math
Ap_db = 10*log10 (pout/pin)

#Result
print"The power gain in decibel is ",round(Ap_db,1),"dB"

The power gain in decibel is  69.7 dB

Example 2.11 Page no 40

In [14]:
#given

gain_db = 28
pin = 36*10**-3

#calculation
pout = 10**2.8*pin;

#Result
print"The output power is ",round(pout,2),"watt"

The output power is  22.71 watt

Example 2.12 Page no 40

In [15]:
#given
gain1 = 6.8 
gain2 = 14.3
attenuation1 = -16.4
attenuation2 = -2.9
vout = 800*10**-3

#calculation
At = gain1+gain2+attenuation1+attenuation2
vin = vout/10.0**(At/20.0)

#Result
print"The input voltage is ",round(vin*10**3,1),"mv"

The input voltage is  650.3 mv

Example 2.13 Page no 40

In [16]:
#given
pout_db =12.3

#calculation
pout_mW = 0.001*10**(12.3/10.0)

#Result
print"The output power is " ,round(pout_mW*10**3,0),"mv"

The output power is  17.0 mv

Example 2.14 Page no 46

In [19]:
#given
c = 2.7*10**-12
l = 33*10**-9

#calculation
fr= 1/(6.28*(l*c)**0.5)

#Result
print"The resonat frequency is " ,round(fr/10.0**6,0),"Mhz"

The resonat frequency is  533.0 Mhz

Example 2.15 Page no 47

In [20]:
#given
c =12*10**-12
fr = 49*10**6

#calculation
l=1/(4*3.14**2*fr**2*c)

#Result
print"The value of inductance is " ,round(l*10**9,0),"nh" 

The value of inductance is  880.0 nh

Example 2.16 Page no 49

In [6]:
#given
fr=28*10**6
Q=70.0

#calculation
bandwidth = fr/Q

#Result
print"The bandwidth is ",bandwidth/10.0**3,"Khz"

The bandwidth is  400.0 Khz

Example 2.17 Page no 50

In [23]:
#given
f1= 7.93*10**6
f2= 8.07*10**6

#calculation
bw= f2-f1
fr=(f1*f2)**0.5
Q= fr/bw

#Result
print"(a) The bandwidth is ",bw/10.0**3,"Khz"
print"(b) The resonant frequency is ",round(fr/10.0**6,0),"Mhz"
print"(c) The Q of resonant circuit is ",round(Q,2)

(a) The bandwidth is  140.0 Khz
(b) The resonant frequency is  8.0 Mhz
(c) The Q of resonant circuit is  57.14

Example 2.18 Page no 50

In [30]:
#given
Q=200.0
fr=16*10**6

#calculation
bw=fr/Q
f1= fr-(bw/2)
f2=fr+(bw/2)

#Result
print"Bandwidth is ",bw*10**-3,"KHz"
print"f1= ",f1*10**-6,"MHz"
print"f2= ",f2*10**-6,"MHz"

Bandwidth is  80.0 KHz
f1=  15.96 MHz
f2=  16.04 MHz

Example 2.19 Page no 52

In [9]:
#given
Q= 150
Vs=3*10**-6

#calculation
Vc= Q*Vs

#Result
print"The voltage across capacitor is ",Vc*10**6,"microvolt"

The voltage across capacitor is  450.0 microvolt

Example 2.20 Page no 54

In [10]:
#given
fr= 52*10**6
Q=12.0
L=0.15*10**-6

#calculation
Rw=(6.28*fr*L)/Q
Req= Rw*(Q**2+1)

#Result
print"Impedance of the parellel LC circuit is ",round(Req,0),"ohm"

Impedance of the parellel LC circuit is  592.0 ohm

Example 2.21 Page no 54

In [13]:
#given
fr= 52.0*10**6
Rw= 4.1
L =0.15*10**-6

#calculation
C=1/(4.0*3.14**2*fr**2*L)
Z = L/(C*Rw)

#Result
print"the impedance of the circuit is ",round(Z,0),"ohm"

the impedance of the circuit is  585.0 ohm

Example 2.22 Page no 55

In [17]:
#given
bw = 1.0*10**6
XL = 300
Rw = 10.0
fr =10*10**6

#calculation
Q1 = XL/Rw
Rp = Rw*(Q1**2+1) 

Q2 = fr/bw
Rpnew = Q2*XL

Rext = (Rpnew*Rp)/(Rp-Rpnew)

#Result
print"The value of resistor needed to set the bandwidth of the parellel tuned circuit is ",round(Rext,1),"ohm"

The value of resistor needed to set the bandwidth of the parellel tuned circuit is  4497.5 ohm

Example 2.23 Page no 57

In [18]:
#given
R = 8.2*10**3
C =0.0033*10**-6

#calculation
fco = 1/(6.28* R*C)

#Result
print"The cut off frequency is ",round(fco/10.0**3,2),"Khz"

The cut off frequency is  5.88 Khz

Example 2.24 Page no 60

In [19]:
#given
fco =3.4*10**3
C = 0.047*10**-6

#calculation
R = 1/(6.28* fco* C)

#Result
print"The value of the resistor is ",round(R,0),"ohm"
print"The closest standard value is ", 1000 ,"ohm"

The value of the resistor is  996.0 ohm
The closest standard value is  1000 ohm

Example 2.25 Page no 61

In [20]:
#given
fnotch = 120
R = 220*10**3

#calculatiuon
C = 1/(6.28*R*fnotch)

#Result
print"The value of capacitance required is ",round(2*C*10**6,3),"microfarad"

The value of capacitance required is  0.012 microfarad

Example 2.26 Page no 82

In [22]:
#given
Vpeak =3.0
f=48*10**3

#calculation
fifth_harmonic = 5*f
Vrms=(4/3.14)*(3/5.0)*0.707

#Result
print"(a) The frequency of the fifth harmonic is ",fifth_harmonic/10.0**3,"Khz"
print"The RMS voltage of the fifth harmonic is ",round(Vrms,3)

(a) The frequency of the fifth harmonic is  240.0 Khz
The RMS voltage of the fifth harmonic is  0.54

Example 2.27 Page no 87

In [25]:
#given
Vpeak = 5
f = 4.0*10**6
duty_cycle=0.3

#calculation
T = 1/f
t0 = duty_cycle*T
Vavg = Vpeak*duty_cycle
min_bw =1/t0

#Result
print"(a) The average DC value is ",Vavg,"volt"
print"(b) The minimum bandwidth required is " ,round(min_bw/10.0**6,3),"Mhz"

(a) The average DC value is  1.5 volt
(b) The minimum bandwidth required is  13.333 Mhz

Example 2.28 Page no 88

In [26]:
#given
tr =6*10**-9

#calculation
min_bw=(35/0.006)

#Result
print"The minimum bandwidth is % is ",round(min_bw/10.0**2,1),"Mhz"

The minimum bandwidth is % is  58.3 Mhz

Example 2.29 Page no 89

In [31]:
#given
bw= 200.0*10**3

#calculation
tr= 0.35/(bw*10**-3)

#Result
print"The fastest rise time of the circuit is " ,tr*10**3,"microseconds"

The fastest rise time of the circuit is  1.75 microseconds

Example 2.30 Page no 90

In [27]:
#given
bw_mhz = 60
tri_ns= 15

#calculation
tra_osci = 0.35/(bw_mhz)
tra_comp = 1.1*(tri_ns**2 + (tra_osci*10**3)**2)**0.5

#Result
print"The rise time of the displayed square wave is ",round(tra_comp,1),"ns"

The rise time of the displayed square wave is  17.7 ns