Explanation:
Expression to calculate thermal resistance for iron ( ) is as follows.
) is as follows.
               
  
where,    = length of the iron bar
 = length of the iron bar
               = thermal conductivity of iron
 = thermal conductivity of iron
               = Area of cross-section for the iron bar
 = Area of cross-section for the iron bar
Thermal resistance for copper ( ) = \frac{L_{c}}{k_{c} \times A_{c}}[/tex]
) = \frac{L_{c}}{k_{c} \times A_{c}}[/tex]
where,   = length of copper bar
 = length of copper bar
               = thermal conductivity of copper
 = thermal conductivity of copper
              = Area of cross-section for the copper bar
 = Area of cross-section for the copper bar
Now, expression for the transfer of heat per unit cell is as follows.
            Q = 
  Putting the given values into the above formula as follows.
        Q = 
   = 
            = 2.92 Joule
It is known that heat transfer per unit time is equal to the power conducted through the rod. Hence, 
                  P = 
 Here, T is 1 second so, power conducted is equal to heat transferred. 
 So,           P = 2.92 watt
Thus, we can conclude that 2.92 watt power will be conducted through the rod when it reaches steady state.