Q. In the Ingen Hauz’s experiment the wax melts up to lengths 10 and $25cm$ on two identical rods of different materials. The ratio of thermal conductivities of the two material is
A) 1 : 6.25
B) 6.25 : 1
C) $1:\sqrt{2.5}$
D) 1 : 2.5
Explanation
(a) $K \propto l^{2} \Rightarrow \frac{K_{1}}{K_{2}} = \frac{l_{1}^{2}}{l_{2}^{2}} = \left( \frac{10}{25} \right)^{2} = \frac{1}{6.25}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.