According to Ingen-Housz experiment, the thermal conductivity k and the length l of the metal rod up to which wax melts are related as
1
\(\dfrac{K}{l}=\rm constant\)
2
\(\dfrac{K^2}{l}=\rm constant\)
3
\(\dfrac{K}{l^2}=\rm constant\)
4
Kl = constant