From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001 From: priyanka Date: Wed, 24 Jun 2015 15:03:17 +0530 Subject: initial commit / add all books --- 2192/CH4/EX4.1/4_1.sce | 16 ++++++++++++++++ 2192/CH4/EX4.10/4_10.sce | 20 ++++++++++++++++++++ 2192/CH4/EX4.11/4_11.sce | 17 +++++++++++++++++ 2192/CH4/EX4.12/4_12.sce | 13 +++++++++++++ 2192/CH4/EX4.13/4_13.sce | 42 ++++++++++++++++++++++++++++++++++++++++++ 2192/CH4/EX4.14/4_14.sce | 21 +++++++++++++++++++++ 2192/CH4/EX4.15/4_15.sce | 22 ++++++++++++++++++++++ 2192/CH4/EX4.16/4_16.sce | 16 ++++++++++++++++ 2192/CH4/EX4.17/4_17.sce | 33 +++++++++++++++++++++++++++++++++ 2192/CH4/EX4.18/4_18.sce | 16 ++++++++++++++++ 2192/CH4/EX4.19/4_19.sce | 30 ++++++++++++++++++++++++++++++ 2192/CH4/EX4.2/4_2.sce | 21 +++++++++++++++++++++ 2192/CH4/EX4.20/4_20.sce | 16 ++++++++++++++++ 2192/CH4/EX4.21/4_21.sce | 16 ++++++++++++++++ 2192/CH4/EX4.22/4_22.sce | 18 ++++++++++++++++++ 2192/CH4/EX4.23/4_23.sce | 25 +++++++++++++++++++++++++ 2192/CH4/EX4.3/4_3.sce | 22 ++++++++++++++++++++++ 2192/CH4/EX4.4/4_4.sce | 16 ++++++++++++++++ 2192/CH4/EX4.5/4_5.sce | 12 ++++++++++++ 2192/CH4/EX4.6/4_6.sce | 14 ++++++++++++++ 2192/CH4/EX4.7/4_7.sce | 24 ++++++++++++++++++++++++ 2192/CH4/EX4.8/4_8.sce | 30 ++++++++++++++++++++++++++++++ 2192/CH4/EX4.9/4_9.sce | 42 ++++++++++++++++++++++++++++++++++++++++++ 23 files changed, 502 insertions(+) create mode 100755 2192/CH4/EX4.1/4_1.sce create mode 100755 2192/CH4/EX4.10/4_10.sce create mode 100755 2192/CH4/EX4.11/4_11.sce create mode 100755 2192/CH4/EX4.12/4_12.sce create mode 100755 2192/CH4/EX4.13/4_13.sce create mode 100755 2192/CH4/EX4.14/4_14.sce create mode 100755 2192/CH4/EX4.15/4_15.sce create mode 100755 2192/CH4/EX4.16/4_16.sce create mode 100755 2192/CH4/EX4.17/4_17.sce create mode 100755 2192/CH4/EX4.18/4_18.sce create mode 100755 2192/CH4/EX4.19/4_19.sce create mode 100755 2192/CH4/EX4.2/4_2.sce create mode 100755 2192/CH4/EX4.20/4_20.sce create mode 100755 2192/CH4/EX4.21/4_21.sce create mode 100755 2192/CH4/EX4.22/4_22.sce create mode 100755 2192/CH4/EX4.23/4_23.sce create mode 100755 2192/CH4/EX4.3/4_3.sce create mode 100755 2192/CH4/EX4.4/4_4.sce create mode 100755 2192/CH4/EX4.5/4_5.sce create mode 100755 2192/CH4/EX4.6/4_6.sce create mode 100755 2192/CH4/EX4.7/4_7.sce create mode 100755 2192/CH4/EX4.8/4_8.sce create mode 100755 2192/CH4/EX4.9/4_9.sce (limited to '2192/CH4') diff --git a/2192/CH4/EX4.1/4_1.sce b/2192/CH4/EX4.1/4_1.sce new file mode 100755 index 000000000..ab70ed9c0 --- /dev/null +++ b/2192/CH4/EX4.1/4_1.sce @@ -0,0 +1,16 @@ +clc,clear +printf('Example 4.1\n\n') + +P=1000 //power absorbed in watts +k_0=8.854*10^-12 //permittivity of free space +k=3.6 //relative permittivity of wood +A=0.5 //area of cross section of plate in m^2 +t=0.025 //thickness in m +f=25*10^6 //frequency in hertz + +C=k_0*k*A/t //capacitance of capacitor formed +phi=acos(0.046) //power factor angle +delta=%pi/2 - phi + +V = sqrt(P/(2*%pi*f*C*delta)) +printf('Voltage employed is %.2f volts',V) diff --git a/2192/CH4/EX4.10/4_10.sce b/2192/CH4/EX4.10/4_10.sce new file mode 100755 index 000000000..b9265d5b0 --- /dev/null +++ b/2192/CH4/EX4.10/4_10.sce @@ -0,0 +1,20 @@ +clc,clear +printf('Example 4.10\n\n') + +P=20*1000 //power supplied in watts +V=220 //supply voltage +e=0.9;k=0.6; //emissivity and radiant efficiency +rho=100*10^-6//specific resistance + +l_by_d2 = %pi*V^2/(4*rho*P) //ratio of l and d^2 (i) +T1=1170+273; T2=500+273; //temperatures of wire and charge +H=5.72*k*e*(T1^4-T2^4)/1000^4 //heat dissipated from surface + +//Surface area = %pi*d*l +//total heat dissipated = electric power input and squaring the equation +d2l2= ( P/(H*%pi) )^2 // d^2 * l^2 (ii) +//using expression (i) and expression (ii) +l =(d2l2*l_by_d2)^(1/3) +printf('Length of wire = %.1f metres',l/100) +d=sqrt( l/l_by_d2 ) +printf('\nSize of wire = %.1f cm',d) diff --git a/2192/CH4/EX4.11/4_11.sce b/2192/CH4/EX4.11/4_11.sce new file mode 100755 index 000000000..660dfcef1 --- /dev/null +++ b/2192/CH4/EX4.11/4_11.sce @@ -0,0 +1,17 @@ +clc,clear +printf('Example 4.11\n\n') + +mass=500 //quantity of brass to be melted +T1=920;T2=20; //final and initial temperature +S=0.094 //specific heat of brass +H1=mass*S*(T1-T2) //heat to raise temperature + +L=39 //latent heat of fusion of brass +H2=mass*L//heat reqd to heat metal at 920 + +H=H1+H2 //total heat required +efficiency=60.2/100 //furnace efficiency +Energy_required = H *4180/(3600*1000*efficiency) //constants used for unit conversion +printf('Energy required = %.1f kWh\n',Energy_required) +time=1/2 //time for melting in hours +printf('Average power input= %.1f kW',Energy_required/time) diff --git a/2192/CH4/EX4.12/4_12.sce b/2192/CH4/EX4.12/4_12.sce new file mode 100755 index 000000000..796c3e4a4 --- /dev/null +++ b/2192/CH4/EX4.12/4_12.sce @@ -0,0 +1,13 @@ +clc,clear +printf('Example 4.12\n\n') + +V=250;R=190 +//part(i) +R1=1/(R^-1+R^-1) //equivalent resistance in parallel +P1=V^2/R1 //power drawn in parallel +printf('(i)Power drawn in parallel = %.2f watts',P1) + +//part(ii) +R2=R+R //equivalent resistance in series +P2=V^2/R2 //power drawn in series +printf('\n(ii)Power drawn in series= %.2f watts',P2) diff --git a/2192/CH4/EX4.13/4_13.sce b/2192/CH4/EX4.13/4_13.sce new file mode 100755 index 000000000..1234b51ff --- /dev/null +++ b/2192/CH4/EX4.13/4_13.sce @@ -0,0 +1,42 @@ +clc,clear +printf('Example 4.13\n\n') + +//PART(i) PART(i) PART(i) PART(i) PART(i) PART(i) PART(i) PART(i) PART(i) PART(i) +V=230;R=100; +P_each = V^2/R + +//part(a) +P1a=6*P_each //power consumed +//part(b) +P1b=V^2/(R+R+R) + V^2/(R+R+R) //power consumed + +//PART(ii) PART(ii) PART(ii) PART(ii) PART(ii) PART(ii) PART(ii) PART(ii) PART(ii) +V=400/sqrt(3) + +//part(a) +R_eq=R/2 //equivalent resistance of given configuration +P2a=V^2/R_eq //power consumed +//part(b) +R_eq=R+R //equivalent resistance of given configuration +P2b=V^2/R_eq //power consumed + +//PART(iii) PART(iii) PART(iii) PART(iii) PART(iii) PART(iii) PART(iii) PART(iii) +V=400 +R_eq=R/2 //equivalent resistance of given configuration +//part(a) +P3a=V^2/R_eq //power consumed +//part(b) +R_eq=R+R //equivalent resistance of given configuration +P3b=V^2/R_eq //power consumed + +printf('Part(i)\n') +printf('(a)Power consumed = %.3f kW\n',P1a/1000) +printf('(b)Power consumed = %.0f watts\n',P1b) +printf('Part(ii)\n') +printf('(a)Power consumed = %.3f kW\n',P2a/1000) +printf('(b)Power consumed = %.3f kW\n',P2b/1000) +printf('Part(iii)\n') +printf('(a)Power consumed = %.1f kW\n',P3a/1000) +printf('(b)Power consumed = %.0f watts\n',P3b) + +printf('\nAnswers may mismatch due to calculation error in book') diff --git a/2192/CH4/EX4.14/4_14.sce b/2192/CH4/EX4.14/4_14.sce new file mode 100755 index 000000000..fed2e0373 --- /dev/null +++ b/2192/CH4/EX4.14/4_14.sce @@ -0,0 +1,21 @@ +clc,clear +printf('Example 4.14\n\n') + +P=15*1000 //power supplied +V=220 //supply voltage +k=0.6;e=0.9; //radiating efficiency and emissivity +rho = 1.016*10^-6 //specific resistance + +l_by_d2 = %pi*V^2/(4*rho*P) //ratio of l and d^2 (i) + +T1=1000+273; T2=600+273; //temperatures of wire and charge +H=5.72*k*e*(T1^4-T2^4)/100^4 //heat dissipated from surface + +//since heat dissipated = electrical power input; +dl2=( P/(H*%pi) )^2//product of d and l (ii) + +//multiplying expression(i) and expression (ii) +l=(l_by_d2*dl2)^(1/3) //length of wire +printf('Length of wire = %.2f m\n',l) +d= sqrt(dl2)/l //diameter of wire +printf('Diameter of wire = %.2f mm',1000*d) diff --git a/2192/CH4/EX4.15/4_15.sce b/2192/CH4/EX4.15/4_15.sce new file mode 100755 index 000000000..b8f4d29a2 --- /dev/null +++ b/2192/CH4/EX4.15/4_15.sce @@ -0,0 +1,22 @@ +clc,clear +printf('Example 4.15\n\n') + +P=30*1000/3 //power per phase +V_ph=400/sqrt(3) //phase voltage +R=(V_ph)^2/P //resistance of strip +t=0.025*10^-2 //thickness of strip +S=1.03*10^-6 //specific resistance of nichrome alloy +l_by_w = R*t/S //because R=specific_resistance*l/(w*t) (i) + +k=0.6;e=0.9; //radiating efficiency and emissivity +T1=1100+273; T2=700+273; //temperatures of wire and charge +H=5.72*k*e*(T1^4-T2^4)/100^4 //heat dissipated from surface + +//surface_area = 2*w*l +//Since, heat dissipated = Power input ; surface_area = P/H +surface_area = P / H +wl=surface_area /2 //product of w and l (ii) + +//dividing expression(ii) by expression(i) +w=sqrt(wl/l_by_w) +printf('Width of strip = %.2f mm',w*1000) diff --git a/2192/CH4/EX4.16/4_16.sce b/2192/CH4/EX4.16/4_16.sce new file mode 100755 index 000000000..d06ed5ce5 --- /dev/null +++ b/2192/CH4/EX4.16/4_16.sce @@ -0,0 +1,16 @@ +clc,clear +printf('Example 4.16\n\n') + +P=1000 //power absorbed in watts +k_0=8.854*10^-12 //permittivity of free space +k=3.6 //relative permittivity of wood +A=0.5 //area of cross section of plate in m^2 +t=0.025 //thickness in m +f=25*10^6 //frequency in hertz + +C=k_0*k*A/t //capacitance of capacitor formed +phi=acos(0.046) //power factor angle +delta=%pi/2 - phi + +V = sqrt(P/(2*%pi*f*C*delta)) +printf('Voltage employed is %.2f volts',V) diff --git a/2192/CH4/EX4.17/4_17.sce b/2192/CH4/EX4.17/4_17.sce new file mode 100755 index 000000000..6a442b438 --- /dev/null +++ b/2192/CH4/EX4.17/4_17.sce @@ -0,0 +1,33 @@ +clc,clear +printf('Example 4.17\n\n') + +m=10*1000 //10 tonnes of steel +S=444//specific heat of steel +L=37.25*1000 //latent heat of fusion of steel +T2=1370;T1=20//final and initial temperatures + +Energy=(m*S*(T2-T1) + m*L) / 3600 //energy required to melt 10 tonne steel in Wh +efficiency= 50/100 +time_taken = 2 //time taken in melting of heat in hours +average_output = Energy/time_taken +average_input= average_output/ efficiency +printf('Average input to furnace = %.1f kW\n',average_input/1000) + +current_input=9000 +resistance= 0.003 //resistance of furnace leads including transformer +reactance= 0.005 //reactance of furnace leads including transformer +V1= current_input*resistance //voltage drop due to resistance +V2= current_input*reactance //voltage drop due to reactance + +//Solving for V_A (arc voltage) +//V_opencircuit= sqrt((V_A=V1)^2+ V2^2) +//cos_phi= V_A+27 / sqrt((V_A-V1)^2+ V2^2) +//Input power = 3*current_input* V_opencircuit *cos_phi + +V_A= average_input/ (3*current_input) -27 +printf('Arc voltage = %.1f V\n',V_A) +V_opencircuit= sqrt((V_A-V1)^2+ V2^2) +total_VA=3*current_input* V_opencircuit +printf('Total kVA taken from supply = %.0f kVA',total_VA/1000) + +printf('\n\nAnswers mimatch because 27 volts was left unconsidered in last 2 steps') diff --git a/2192/CH4/EX4.18/4_18.sce b/2192/CH4/EX4.18/4_18.sce new file mode 100755 index 000000000..cf449e3a0 --- /dev/null +++ b/2192/CH4/EX4.18/4_18.sce @@ -0,0 +1,16 @@ +clc,clear +printf('Example 4.18\n\n') + +m=1.8 //mass of aluminium to be melt +t1=15 //initial temperature +t2=660 //melting temperature + +S=880 //specific heat of aluminium +L=32000 //latent heat of aluminium + +heat_required= m*S*(t2-t1) + m*L +heat_required= heat_required*2.78*10^-7 //converting Joules to kWh +T=10//time taken for melting in minutes +energy_input=5*(T/60) //In kWh +efficiency_of_furnace = 100* heat_required / energy_input +printf('Efficiency of furnace = %.0f percent',efficiency_of_furnace ) diff --git a/2192/CH4/EX4.19/4_19.sce b/2192/CH4/EX4.19/4_19.sce new file mode 100755 index 000000000..a4999ad10 --- /dev/null +++ b/2192/CH4/EX4.19/4_19.sce @@ -0,0 +1,30 @@ +clc,clear +printf('Example 4.19\n\n') + +arc_voltage=50 +I=5000 //current drawn +resistance= 0.002 //resistance of furnace leads including transformer +reactance= 0.004 //reactance of furnace leads including transformer +V1= I*resistance //voltage drop due to resistance of transformer +V2= I*reactance //voltage drop due to reactance of transformer +V_OC= sqrt( (arc_voltage+V1)^2 + V2^2 ) //open circuit phase voltage of transformer secondary + +//part(i) +pf=(arc_voltage+V1)/V_OC +power_drawn= I*V_OC*pf //power drawn from supply per phase +total_power_drawn =power_drawn*3 +printf('Power factor of supply = %.4f\n',pf) +printf('kW drawn from supply= %.0f kW\n',total_power_drawn/1000) + +//part(ii) +m=2*10^3 //mass of steel to melt +S=120//specific heat of steel +L=8890//latent heating of fusion +T2=1370;T1=20; //melting point and initial temperature +efficiency=65/100//efficiency of furnace +energy_required= ( m*S*(T2-T1) + m*L) /869 //energy reqd to melt steel in watts +power_utilised= total_power_drawn * efficiency +time= energy_required /power_utilised //time required for melting +printf('Time required for melting = %d minutes %d seconds\n\n',60*time,60*(60*time- floor(60*time) )) + +printf('Answers might slightly vary due to lack of accuracy in energy required calculation') diff --git a/2192/CH4/EX4.2/4_2.sce b/2192/CH4/EX4.2/4_2.sce new file mode 100755 index 000000000..57aa9be25 --- /dev/null +++ b/2192/CH4/EX4.2/4_2.sce @@ -0,0 +1,21 @@ +clc,clear +printf('Example 4.2\n\n') + +P=16*1000 //power supplied in watts +V=220 //supply voltage +e=0.9;k=0.57; //emissivity and radiant efficiency +rho=1.09*10^-12//resistivity in ohm-metre + +l_by_d2 = %pi*V^2/(4*rho*P) //ratio of l and d^2 (i) +T1=1170+273; T2=500+273; //temperatures of wire and charge +H=5.72*k*e*(T1^4-T2^4)/100^4 //heat dissipated from surface + +//Surface area = %pi*d*l +//total heat dissipated = electric power input and squaring the equation +d2l2= ( P/(H*%pi) )^2 //d^2*l^2 (ii) +//multiplying expression (i) and expression (ii) +l =(1/100)*(d2l2*l_by_d2)^(1/3) +printf('Length of wire = %.0f metre',l) +d=1000*sqrt(d2l2)/l +//d=sqrt( l/l_by_d2 ) +printf('\nDiameter of wire = %.2f mm',d) diff --git a/2192/CH4/EX4.20/4_20.sce b/2192/CH4/EX4.20/4_20.sce new file mode 100755 index 000000000..7a422f62b --- /dev/null +++ b/2192/CH4/EX4.20/4_20.sce @@ -0,0 +1,16 @@ +clc,clear +printf('Example 4.20\n\n') + +V=10 //secondary voltage +P=400*10^3 //power drawn in watts +phi=acos(0.6) //power factor angle +I= P/(V*cos(phi)) //secondary current +Z=V/I //impedance of secondary circuit +R=Z*cos(phi) //resistance of secondary circuit when hearth is full +X=Z*sin(phi) //reactance of secondary circuit + +//x is ratio of height of charge to full hearth +//Heat produced will be maximum when resistance of secondary circuit equals reactance ; i.e. when R/x= X + +x=R/X +printf('Height of charge should be %.2f times height of hearth to obtain maximum heat',x) diff --git a/2192/CH4/EX4.21/4_21.sce b/2192/CH4/EX4.21/4_21.sce new file mode 100755 index 000000000..d56513246 --- /dev/null +++ b/2192/CH4/EX4.21/4_21.sce @@ -0,0 +1,16 @@ +clc,clear +printf('Example 4.21\n\n') + +V= 0.5*0.25*0.02//volume of plywood to be heated +D=600 //density of plywood in kg/m^3 +W=V*D + +specific_heat = 1500 +T1=25;T2=125; //initial and final temperature +heat= specific_heat * W * (T2-T1)/(60*60) //in W-Hr +T=10 //duration of heating in minutes +power_required = heat/(T/60) +efficiency= 50/100 //efficiency of process +power_input= power_required/ efficiency + +printf('Power required for heating = %.0f watts',power_input) diff --git a/2192/CH4/EX4.22/4_22.sce b/2192/CH4/EX4.22/4_22.sce new file mode 100755 index 000000000..353b3166c --- /dev/null +++ b/2192/CH4/EX4.22/4_22.sce @@ -0,0 +1,18 @@ +clc,clear +printf('Example 4.22\n\n') + +P=200//power absorbed in watts +phi=acos(0.05) //power factor angle +f=3*10^6 //supply frequency in hertz +k_0=8.854*10^-12 //permittivity of free space +k=5 //relative permittivity of material +A=1500*10^-6 //Area of slab +t=20*10^-3 //thickness of insulating material + +C=k_0*k*A/t //capacitance of capacitor formed +V=sqrt(P/(2*%pi*f*C*cos(phi))) //voltage required +printf('Voltage required for heating = %.0f V',V) +I=P/(V*cos(phi)) //current flowing through material +printf('\nCurrent flowing through material = %.1f A',I) + +printf('\n\nWARNING :Answers may not match due to rounding off') diff --git a/2192/CH4/EX4.23/4_23.sce b/2192/CH4/EX4.23/4_23.sce new file mode 100755 index 000000000..254b07bc6 --- /dev/null +++ b/2192/CH4/EX4.23/4_23.sce @@ -0,0 +1,25 @@ +clc,clear +printf('Example 4.23\n\n') + +A1= (25-5)*2*10^-4 //area of air envelope +A2=5*2*10^-4 //Area of plywood in m^2 +t=2/100 //distance between electrodes +t1=1/100 //thickness of plywood in m +t2=(2-1)/100 //thickness of air envelope +eps_0 = 8.854*10^-12 //permittivity of free space +eps_r1 =5 //relative permittivity of plywood +eps_r2 =1 //relative permittivity of air + +//capacitance of capacitor +C= eps_0 * ( (A1*eps_r2/t) + (A2/((t1/eps_r1)+(t2/eps_r2))) ) + +P=1000 //power consumed +f=10*10^6 //frequency of electric current +phi=acos(0.04) //power factor angle + +//part(i) +V = sqrt(P/(2*%pi*f*C*cos(phi))) //voltage across the electrode +printf('(i)Voltage across the electrode = %.0f V',V) +//part(ii) +I=P/(V*cos(phi)) //current through plywood +printf('\n(ii)Current through plywood = %.3f A',I) diff --git a/2192/CH4/EX4.3/4_3.sce b/2192/CH4/EX4.3/4_3.sce new file mode 100755 index 000000000..96761746a --- /dev/null +++ b/2192/CH4/EX4.3/4_3.sce @@ -0,0 +1,22 @@ +clc,clear +printf('Example 4.3\n\n') + +P=30*10^3/3 //power per phase +V_ph=400/sqrt(3) //phase voltage +R=(V_ph)^2/P + +//l and w are length and width respectively +rho= 101.6*10^-8 //resistivity +t=0.254*10^-3 //thickness of nickel-chrome strip +l_by_w = R*t/rho //ratio of l and w (i) + +k=0.5;e=0.9; //radiating efficiency and emissivity +T1=1100+273; T2=700+273; //temperatures of wire and charge +H=5.72*k*e*(T1^4-T2^4)/100^4 //heat dissipated from surface + +//surface are for heat dissipation = 2*w*l +//heat dissipated = power input +wl= P/(2*H) // (ii) +//dividing expression (ii) by expression (i) +w= sqrt(wl/l_by_w) +printf('Width of strip = %.1f mm',w*1000) diff --git a/2192/CH4/EX4.4/4_4.sce b/2192/CH4/EX4.4/4_4.sce new file mode 100755 index 000000000..7612dd32c --- /dev/null +++ b/2192/CH4/EX4.4/4_4.sce @@ -0,0 +1,16 @@ +clc,clear +printf('Example 4.4\n\n') + +surface_area= 6 //surface area of tank +l=sqrt(surface_area/6) //length of one side of tank +volume=l^3 +m=6*90/100 * 1000 //mass of water to be heated daily in kilogram +S=4200//specific heat of water +t2=65;t1=20;//final and initial temperature +heat=m*S*(t2-t1)*10^-6 /3.6 // heat required for raising the temperature in kWh +losses =6.3*surface_area*(t2-t1)*24/1000 //losses from surface of tank 24 hours in kWh +energy_supplied= heat+losses +loading= energy_supplied/24 //in kW +printf('Loading = %.1f kW\n',loading) +efficiecny=100*heat/energy_supplied +printf('Efficiency of tank = %.1f percent',efficiecny) diff --git a/2192/CH4/EX4.5/4_5.sce b/2192/CH4/EX4.5/4_5.sce new file mode 100755 index 000000000..08c988f67 --- /dev/null +++ b/2192/CH4/EX4.5/4_5.sce @@ -0,0 +1,12 @@ +clc,clear +printf('Example 4.5\n\n') + +m=2.5 //quantity of aluminium to be melted +t1=15;t2=658;//melting point and initial temperature +S=0.212 *1000*4.18 //specific bheat of aluminium +L=320000//latent heat of aluminium +W=( m*S*(t2-t1) + m*L ) *10^-6/ 3.6 // heat required for melting in kWh +energy_input = 5*15/60 //converting to kWh +efficiency = 100*W/energy_input //efficiency of furnace + +printf('Efficiency of furnace = %.1f percent',efficiency) diff --git a/2192/CH4/EX4.6/4_6.sce b/2192/CH4/EX4.6/4_6.sce new file mode 100755 index 000000000..7a7049aca --- /dev/null +++ b/2192/CH4/EX4.6/4_6.sce @@ -0,0 +1,14 @@ +clc,clear +printf('Example 4.6\n\n') + +P=400 //power absorbed in watts +phi=acos(0.05) //power factor angle +f=30*10^6 //frequency in hertz +k_0=8.854*10^-12 //permittivity of free space +k=5 //relative permittivity of wood +A=150*10^-4 //area of cross section of plate in m^2 +t=0.01 //thickness in m + +C=k_0*k*A/t //capacitance of capacitor formed +V = sqrt(P/(2*%pi*f*C*cos(phi))) +printf('Necessary voltage is %.2f volts',V) diff --git a/2192/CH4/EX4.7/4_7.sce b/2192/CH4/EX4.7/4_7.sce new file mode 100755 index 000000000..b8ace9951 --- /dev/null +++ b/2192/CH4/EX4.7/4_7.sce @@ -0,0 +1,24 @@ +clc,clear +printf('Example 4.7\n\n') + +P=400 //power absorbed in watts +phi=acos(0.05) //power factor angle +f=40*10^6 //frequency in hertz +k_0=8.854*10^-12 //permittivity of free space +k=5 //relative permittivity of wood +A=200*10^-4 //area of cross section of plate in m^2 +t=0.02 //thickness in m + +C=k_0*k*A/t //capacitance of capacitor formed + +V = sqrt(P/(2*%pi*f*C*cos(phi))) +printf('Necessary voltage is %.0f volts',V) + +I=P/(V*cos(phi)) +printf('\nCurrent flowing through material is %.3f Amp',I) + +//heat produced=f*V^2 ; +V_2=700 //new limited voltage +f2 = f*(V/V_2)^2 +printf('\nRequired frequency is %.1f*10^6 Hz',f2/10^6) + diff --git a/2192/CH4/EX4.8/4_8.sce b/2192/CH4/EX4.8/4_8.sce new file mode 100755 index 000000000..c8d7626e6 --- /dev/null +++ b/2192/CH4/EX4.8/4_8.sce @@ -0,0 +1,30 @@ +clc,clear +printf('Example 4.8\n\n') + +arc_voltage=50 +I=5000 //current drawn +resistance= 0.002 //resistance of furnace leads including transformer +reactance= 0.004 //reactance of furnace leads including transformer +V1= I*resistance //voltage drop due to resistance of transformer +V2= I*reactance //voltage drop due to reactance of transformer +V_OC= sqrt( (arc_voltage+V1)^2 + V2^2 ) //open circuit phase voltage of transformer secondary + +//part(i) +pf=(arc_voltage+V1)/V_OC +power_drawn= I*V_OC*pf //power drawn from supply per phase +total_power_drawn =power_drawn*3 +printf('Power factor of supply = %.4f\n',pf) +printf('kW drawn from supply= %.0f kW\n',total_power_drawn/1000) + +//part(ii) +m=2*10^3 //mass of steel to melt +S=120//specific heat of steel +L=8890//latent heating of fusion +T2=1370;T1=20; //melting point and initial temperature +efficiency=65/100//efficiency of furnace +energy_required= ( m*S*(T2-T1) + m*L) /869 //energy reqd to melt steel in watts +power_utilised= total_power_drawn * efficiency +time= energy_required /power_utilised //time required for melting +printf('Time required for melting = %d minutes %d seconds\n\n',60*time,60*(60*time- floor(60*time) )) + +printf('Answers might slightly vary due to lack of accuracy in energy required calculation') diff --git a/2192/CH4/EX4.9/4_9.sce b/2192/CH4/EX4.9/4_9.sce new file mode 100755 index 000000000..833539e2f --- /dev/null +++ b/2192/CH4/EX4.9/4_9.sce @@ -0,0 +1,42 @@ +clc,clear +printf('Example 4.9\n\n') + +//PART(i) PART(i) PART(i) PART(i) PART(i) PART(i) PART(i) PART(i) PART(i) PART(i) +V=230;R=100; +P_each = V^2/R + +//part(a) +P1a=6*P_each //power consumed +//part(b) +P1b=V^2/(R+R+R) + V^2/(R+R+R) //power consumed + +//PART(ii) PART(ii) PART(ii) PART(ii) PART(ii) PART(ii) PART(ii) PART(ii) PART(ii) +V=400/sqrt(3) + +//part(a) +R_eq=R/2 //equivalent resistance of given configuration +P2a=V^2/R_eq //power consumed +//part(b) +R_eq=R+R //equivalent resistance of given configuration +P2b=V^2/R_eq //power consumed + +//PART(iii) PART(iii) PART(iii) PART(iii) PART(iii) PART(iii) PART(iii) PART(iii) +V=400 +R_eq=R/2 //equivalent resistance of given configuration +//part(a) +P3a=V^2/R_eq //power consumed +//part(b) +R_eq=R+R //equivalent resistance of given configuration +P3b=V^2/R_eq //power consumed + +printf('Part(i)\n') +printf('(a)Power consumed = %.3f kW\n',P1a/1000) +printf('(b)Power consumed = %.0f watts\n',P1b) +printf('Part(ii)\n') +printf('(a)Power consumed = %.3f kW\n',P2a/1000) +printf('(b)Power consumed = %.3f kW\n',P2b/1000) +printf('Part(iii)\n') +printf('(a)Power consumed = %.1f kW\n',P3a/1000) +printf('(b)Power consumed = %.0f watts\n',P3b) + +printf('\nAnswers may mismatch due to calculation error in book') -- cgit