//Chapter-3, Example 3.23, Page 89 //============================================================================= clc clear //INPUT DATA p=100;//Resistivity of nichrome in ยต ohm-cm Q=10000;//Heat input of a heater in W T=1220;//Surface temperature of nichrome in degree C Ta=20;//Temperature of surrounding air in degree C h=1150;//Outside surface coeffient in W/m^2.K k=17;//Thermal conductivity of nichrome in W/m.K L=1;//Length of heater in m //CALCULATIONS d=(Q/((T-Ta)*3.14*h))*1000;//Diameter of nichrome wire in mm A=(3.14*d*d)/4;//Area of the wire in m^2 R=((p*10^-8*L)/A);//Resistance of the wire in ohm I=sqrt(Q/R)/1000;//Rate of current flow in A //OUTPUT mprintf('Diameter of nichrome wire is %3.4f mm \n Rate of current flow is %i A',d,I) //=================================END OF PROGRAM==============================