In [1]:

```
import math
# Variables
T = 5527; #Temperature of black body in degree C
D = (1.39*10**6); #Diameter of the sun in km
L = (1.5*10**8); #Distance between the earth and sun in km
# Calculations
q = (5.67*10**-8*(T+273)**4*D**2)/(4*L**2); #Rate of solar radiation in W/m**2
# Results
print 'Rate of solar radiation on a plane normal to sun rays is %3.0f W/m**2'%(q)
```

In [2]:

```
# Variables
T = (727+273); #Temperature of black body in K
l1 = 1; #Wavelength in micro meter
l2 = 5; #Wavelength in micro meter
F1 = 0.0003; #From Table 9.2 on page no. 385
F2 = 0.6337; #From Table 9.2 on page no. 385
# Calculations
a = (5.67*10**-8*T**4)/1000; #Heat transfer in kW/m**2
F = (F2-F1)*a; #Fraction of thermal radiation emitted by the surface in kW/m**2
# Results
print 'Fraction of thermal radiation emitted by the surface is %3.1f kW/m**2'%(F)
```

In [3]:

```
# Variables
t = 0.8; #Transmittivity of glass in the region except in the wave length region [0.4,3]
T = 5555; #Temperature of black body in K
# Calculations
ao = 0; #a0 in micro K
a1 = (0.4*T); #a1 for the wavelength 0.4 micro meter in micro K
a2 = (3*T); #a1 for the wavelength 3 micro meter in micro K
F0 = 0; #From Table 9.2 on page no.385
F1 = 0.10503; #From Table 9.2 on page no.385
F2 = 0.97644; #From Table 9.2 on page no.385
t1 = t*(F2-F1); #Average hemispherical transmittivity of glass
# Results
print 'Average hemispherical transmittivity of glass is %3.2f'%(t1)
```

In [1]:

```
# Variables
l = 0.5; #Wavelength at maximum intensity of radiation in micro meter
C3 = 0.289*10**-2 #mK
# Calculations
T = C3/(l*10**-6); #Temperature according to Wien's print lacement law in degree C
E = (5.67*10**-8*T**4)/10**6; #Emissive power umath.sing Stefan-Boltzmann law in MW/m**2
# Results
print 'Surface temperature is %3.0f K Emissive power is %3.1f MW/m**2'%(T,E)
```

In [6]:

```
# Variables
Ts = (827+273); #Surface temperature in degree C
E = (1.37*10**10); #Emmisive power in W/m**3
# Calculations
Eblmax = (1.307*10**-5*Ts**5); #Maximum emissive power in W/m**3
e = (E/Eblmax); #Emissivity of the body
lmax = ((0.289*10**-2)/Ts)/10**-6; #Wavelength correspoing to the maximum spectral intensity of radiation in micro meter
# Results
print 'Wavelength corresponding to the maximum spectral intensity of radiation is %3.2f micro meter'%(lmax)
```

In [7]:

```
import math
# Variables
T = (1400+273); #Temperature of the body in K
l = 0.65; #Wavelength in micro meter
e = 0.6; #Emissivity
# Calculations
T = (1./((1./T)-((l*10**-6*math.log(1./e))/(1.439*10**-2)))); #Temperature of the body in K
Tb = (T-273); #Temperature of the body in degree C
# Results
print 'Temperature of the body is %3.0f degree C'%(Tb)
```

In [2]:

```
# Variables
Ts = (37+273); #Temperature of metallic bar in K
T = 1100; #Interior temperature in K
a = 0.52; #Absorptivity at 1100 K
e = 0.8; #Emissivity at 310 K
# Calculations
Q = (a*5.67*10**-8*T**4)/1000; #Rate of absorption in kW/m**2
E = (e*5.67*10**-8*Ts**4)/1000; #Rate of emission in kW/m**2
# Results
print 'Rate of absorption is %3.2f kW/m**2 \n \
Rate of emission is %3.2f kW/m**2'%(Q,E)
```

In [9]:

```
# Variables
e1 = 0.3 #Emissivity of glass upto 3 micro meter
e2 = 0.9; #Emissivity of glass above 3 micro meter
t = 0.8; #Transmittivity of glass in the region except in the wave length region [0.4,3]
# Calculations
E = (5.67*10**-8*5780**4)/10**6; #Emissive power in MW/m**2
F1 = 0.10503; #From Table 9.2 on page no.385
F2 = 0.97644; #From Table 9.2 on page no.385
I = (E*10**6*(F2-F1))/10**6; #Total incident radiation in MW/m**2
T = (t*I); #Total radiation transmitted in MW/m**2
t1 = (e1*I); #Absorbed radiation in MW/m**2 in wavelength [0.4,3] micro meter
t2 = (e1*E*F1); #Absorbed radiation in MW/m**2 in wavelength not in the range [0.4,3] micro meter
t3 = (e2*(1-F2)*E); #Absorbed radiation in MW/m**2 in wavelength greater than 3 micro meter
R = (t1+t2+t3); #Total radiation absorbed in MW/m**2
# Results
print 'Total radiation transmitted is %3.2f MW/m**2 \n \
Total radiation absorbed is %3.2f MW/m**2'%(T,R)
```