Discussion Forum
Que.  The mean thermal conductivity evaluated at the arithmetic mean temperature is represented by 
a.  km = k0 [1 + β (t1 – t2)/2]. 
b.  km = k0 [1 + (t1 + t2)/2]. 
c.  km = k0 [1 + β (t1 + t2)/3]. 
d.  km = k0 [1 + β (t1 + t2)/2]. 
Correct Answer:km = k0 [1 + β (t1 + t2)/2].
