7 files changed, 95 insertions, 0 deletions
diff --git a/2300/CH12/EX12.9.1/Ex12_1.sce b/2300/CH12/EX12.9.1/Ex12_1.sce
new file mode 100755
index 000000000..3520d6b57
--- /dev/null
+++ b/2300/CH12/EX12.9.1/Ex12_1.sce
@@ -0,0 +1,13 @@
+//scilab 5.4.1
+//Windows 7 operating system
+//chapter 12 Modulation and Demodulation
+clc
+clear
+Vmax=8//Vmax=maximum peak to peak value of an AM voltage
+Vmin=2//Vmin=minimum peak to peak value of an AM voltage
+ma=(Vmax-Vmin)/(Vmax+Vmin)//ma=percentage modulation 
+disp("%",(ma*100),"Percentage modulation ma=")
+//ma=(Vmax-Vmin)/(2*VC) where VC=amplitude of the unmodulated carrier
+VC=(Vmax-Vmin)/(2*ma)
+disp("V",VC,"Amplitude of the unmodulated carrier is VC=")
+disp("In the textbook answer given is incorrect as they have further divided by 2 which is not the part of given formula.")
diff --git a/2300/CH12/EX12.9.2/Ex12_2.sce b/2300/CH12/EX12.9.2/Ex12_2.sce
new file mode 100755
index 000000000..1bb511d28
--- /dev/null
+++ b/2300/CH12/EX12.9.2/Ex12_2.sce
@@ -0,0 +1,16 @@
+//scilab 5.4.1
+//Windows 7 operating system
+//chapter 12 Modulation and Demodulation
+clc
+clear
+fc=1000*(10^3)//fc=frequency of the carrier wave in Hz(hertz)
+fmin=400
+fmax=1600//fmin and fmax represent the frequency range of audio signals by which the carrier wave is amplitude modulated.
+fs=fmax-fmin//fs=frequency span of each sideband
+disp("Hz",fs,"1.Frequency span of each sideband is ")
+fumax=(fc+fmax)/1000//fumax=maximum upper side frequency
+disp("kHz",fumax,"2.The maximum upper side frequency is ")
+flmin=(fc-fmax)/1000//flmin=minimum lower side frequency
+disp("kHz",flmin,"3.The minimum lower side frequency is ")
+Wc=fumax-flmin//Wc=channelwidth
+disp("kHz",Wc,"4.The channelwidth is ")
diff --git a/2300/CH12/EX12.9.3/Ex12_3.sce b/2300/CH12/EX12.9.3/Ex12_3.sce
new file mode 100755
index 000000000..080de4732
--- /dev/null
+++ b/2300/CH12/EX12.9.3/Ex12_3.sce
@@ -0,0 +1,13 @@
+//scilab 5.4.1
+//Windows 7 operating system
+//chapter 12 Modulation and Demodulation
+clc
+clear
+R=100//R=load resistance in ohms
+Vc=100//Vc=peak voltage of the carrier in volts
+ma=0.4//ma=modulation factor
+Pc=(Vc^2)/(2*R)//Pc=unmodulated carrier power developed by an AM wave
+disp("W",Pc,"The unmodulated carrier power is Pc= ")
+Pt=Pc*(1+((ma^2)/2))//Pt=total power developed
+disp("W",Pt,"The total power developed by the AM wave is Pt=")
+
diff --git a/2300/CH12/EX12.9.4/Ex12_4.sce b/2300/CH12/EX12.9.4/Ex12_4.sce
new file mode 100755
index 000000000..a47428a6f
--- /dev/null
+++ b/2300/CH12/EX12.9.4/Ex12_4.sce
@@ -0,0 +1,13 @@
+//scilab 5.4.1
+//Windows 7 operating system
+//chapter 12 Modulation and Demodulation
+clc
+clear
+ma=0.5//ma=modulation factor
+Pc=20//Pc=unmodulated carrier power in kilowatts(kW)
+Ps=(1/2)*(ma^2)*Pc//Ps=total sideband power
+disp("kW",Ps,"The total sideband power is Ps=")
+//modulator system efficiency is given as 70 per cent
+Pa=Ps/0.7//Pa=audio power necessary toamplitude modulate a given carrier wave
+format("v",5)
+disp("kW",Pa,"The required audio power is ")
diff --git a/2300/CH12/EX12.9.5/Ex12_5.sce b/2300/CH12/EX12.9.5/Ex12_5.sce
new file mode 100755
index 000000000..61918ab2c
--- /dev/null
+++ b/2300/CH12/EX12.9.5/Ex12_5.sce
@@ -0,0 +1,14 @@
+//scilab 5.4.1
+//Windows 7 operating system
+//chapter 12 Modulation and Demodulation
+clc
+clear
+df=30//df=maximum frequency deviation in kilohertz(kHz)
+fm=15//fm=modulation frequency of a sinusoidal audio signal in kilohertz(kHz)
+mf=df/fm//mf=frequency modulation index
+disp(mf,"1.The modulation index is mf=")
+fc=100//fc=carrier wave frequency in megahertz(MHz)
+disp("2.The three significant pairs of side frequencies are 100MHz+-15kHz(fc+-fm);100MHz+-30kHz(fc+-2fm);100MHz+-45kHz(fc+-3fm)")
+wc=mf*3*fm//wc=channelwidth required for 3 above mentioned side frequency pairs
+disp("kHz",wc,"3.The required channelwidth is ")
+
diff --git a/2300/CH12/EX12.9.6/Ex12_6.sce b/2300/CH12/EX12.9.6/Ex12_6.sce
new file mode 100755
index 000000000..9caa8541b
--- /dev/null
+++ b/2300/CH12/EX12.9.6/Ex12_6.sce
@@ -0,0 +1,13 @@
+//scilab 5.4.1
+//Windows 7 operating system
+//chapter 12 Modulation and Demodulation
+clc
+clear
+R=0.2*(10^6)//R=load resistance in ohms in a diode detector 
+C=150*(10^-12)//C=capacitance in farad in a diode detector 
+//fmh=wmh/(2*%pi)where fmh=highest modulation frequency that can be detected with tolerable distortion and wmh=corresponding angular frequency
+ma=0.5//ma=modulation factor or depth of modulation
+fmh=(1/(2*%pi*ma*R*C))/1000
+format("v",6)
+disp("kHz",fmh,"The required frequency is fmh=")
+
diff --git a/2300/CH12/EX12.9.7/Ex12_7.sce b/2300/CH12/EX12.9.7/Ex12_7.sce
new file mode 100755
index 000000000..d01799c48
--- /dev/null
+++ b/2300/CH12/EX12.9.7/Ex12_7.sce
@@ -0,0 +1,13 @@
+//scilab 5.4.1
+//Windows 7 operating system
+//chapter 12 Modulation and Demodulation
+clc
+clear
+Pc=10//Pc=unmodulated carrier power in kilowatts(kW)
+Pt=12.5//Pt=total power in kilowatts(kW)
+//Pt=Pc*(1+((ma^2)/2)) 
+ma=sqrt(2*((Pt/Pc)-1))//ma=depth of modulation of the first signal
+disp(ma,"The depth of modulation is ma=")
+mb=0.6//mb=depth of modulation of the second signal
+PT=Pc*(1+((ma^2)/2)+((mb^2)/2))//PT=the total radiated power
+disp("kW",PT,"The total radiated power is PT=")