In [1]:

```
# Variables
k = 0.12; #thermal conductivity in cgs unit
t1 = 200; #temperature at one side in deg.C
t2 = 50; #temperature at other side in deg.C
t = 3600; #time in sec
a = 1; #area in sq.cm
t3 = 3; #thickness of the plate in cm
# Calculations
q = k*a*(t1-t2)*t/t3; #amount of heat conducted in cal
# Result
print 'the amount of heat conducted is %3.2f cal'%(q)
```

In [2]:

```
# Variables
k = 0.9; #thermal conductivity in cgs unit
a = 10; #area of the copper bar in sq.cm
t1 = 100; #hot side temperature in deg.C
t2 = 20; #cool side temperature in deg.C
d = 25; #thickness of the bar in cm
t3 = 14; #temperature of water when entering in deg.C
# Calculations
m = k*a*(t1-t2)/(d*(t2-t3)); #rate flow of water in gm/sec
# Result
print 'rate flow of water is %3.2f gm/sec'%(m)
```

In [3]:

```
# Variables
i = 1.18; #current in amperes
e = 20; #potential difference across its ends in volts
j = 4.2; #joules constant in joule/cal
a = 2*10**4; #area of the slab in sq.cm
t = 5; #thickness of the plate in cm
t1 = 12.5; #temperature at hot side in K
t2 = 0; #temperature at cold side in k
# Calculations
k = e*i*t/(j*a*(t1-t2)); #thermal conductivity in cgs unit
# Result
print 'thermal conductivity of slab is %3.5f cgs unit'%(k)
```

In [4]:

```
import math
# Variables
l = 30.; #length of the tube in cm
t = 100.; #temperature at outside in deg.C
t1 = 40.; #tempertaure of water when leaving tube in deg.C
t2 = 20.; #temperature of water when entering tube in deg.C
m = 165./60 #mass flow rete of water in cc/sec
r1 = 6.; #internal radii in mm
r2 = 8.; #external radii in mm
# Calculations
k = m*(t1-t2)*math.log(r2/r1)/(2*3.14*l*(t-((t1+t2)/2))); #thermal conductivity in cgs unit
# Result
print 'thermal conductivity of the tube is %3.4f cgs unit'%(k)
```

In [5]:

```
# Variables
l1 = 1.9; #length of the first bar in cm
l2 = 5; #length of the second bar in cm
k2 = 0.92; #thermal conductivity in cgs unit
# Calculations
k1 = k2*(l1/l2)**2; #thermal conductivity if first bar in cgs unit
# Result
print 'thermal conductivity of first bar is %3.3f cgs unit'%(k1)
```

In [6]:

```
# Variables
k1 = 0.92; #thermal conductivity of copper in cgs unit
k2 = 0.5; #thermal conductivity of alluminium in cgs unit
t1 = 100; #temperature of copper in deg.C
t2 = 0; #temperature of alluminium in deg.C
# Calculations
t = k1*t1/(k1+k2); #welded teperature in deg.C
# Result
print 'welded temperature is %3.1f deg.C'%(t)
```

In [9]:

```
# Variables
w = 23; #thermal capacity of calorimeter in cal
m = 440; #mass of water in gm
l = 14.6; #lenght of the rubber tube in cm
dt = 0.019; #rate of change in temperature in deg.C/sec
t = 100; #temperature of steam in deg.C
t1 = 22; #temperature of the water in deg.C
t2 = t1; #temperature of calorimeter in deg.C
r1 = 1; #external radii in cm
r2 = 0.75; #internal radii in cm
# Calculations
k = (w+m)*dt*math.log(r1/r2)/(2*3.14*l*(t-((t1+t2)/2))); #thermal conductivity in cgs unit
# Result
print 'thermal cnductivity of rubber tube is %3.6f cgs unit'%(k)
```

In [10]:

```
# Variables
ti = 18; #inside temperature in deg.C
to = 4; #outside temperature in deg.C
k1 = 0.008; #thermal conductivity of stone in cgs unit
k2 = 0.12; #thermal conductivity of steel in cgs unit
t = 3600; #time in sec
t1 = 25; #thickness of the stone in cm
t2 = 2; #thickness of the steel in cm
a = 10**4; #area of the cottage in sq.cm
# Calculations
q1 = k1*a*(ti-to)*t/(t1); #heat lost by stone per hour in cal
q2 = k2*a*(ti-to)*t/t2; #heat lost by steel per hour in cal
# Result
print 'heat lost by stone is %3.4e cal \
\nheat lost by steel is %.3e cal'%(q1,q2)
```

In [11]:

```
# Variables
l1 = 4; #length of the slab1 in cm
l2 = 2; #length of the slab2 in cm
k1 = 0.5; #thermal conductivity in cgs unit
k2 = 0.36; #thermal conductivity in cgs unit
t1 = 100; #temperature of the slab1 in deg.C
t2 = 0; #temperature of the slab2 in deg.C
# Calculations
t = k1*l2*t1/((k2*l1)+(k1*l2)); #temperature of the commaon surface in deg.C
# Result
print 'the temperature of the common surface is %3.0f deg.C'%(t)
```

In [14]:

```
# The distance
# Variables
t1 = 15.; #temperature of the one end of the slab in deg.C
t2 = 45.; #temperature of the other end of the slab in deg.C
k = 0.3; #thermal conductivity in cgs unit
d = 7.; #density of the material in gm/cc
cp = 1.; #specific heat of the material in kj/kg.K
t = 5.*3600; #time in sec
dt = 1./10; #thermometer reading in deg.C
# Calculations
b = (3.14*d*cp/(t*k))**(0.5);
x = (math.log((t2-t1)/dt))/b; #distance from which temparature variation can be detected in cm
# Result
print 'the distance from which temparature variation can be detected is %3.1f cm'%(x)
```