A copper rod $2\,m$ long has a circular cross-section of radius $1\, cm$. One end is kept at $100^o\,C$ and the other at $0^o\,C$ and the surface is covered by nonconducting material to check the heat losses through the surface. The thermal resistance of the bar in degree kelvin per watt is (Take thermal conductivity $K = 401\, W/m-K$ of copper):-
$12.9$
$13.9$
$14.9$
$15.9$
Two rods $A$ and $B$ of same cross-sectional are $A$ and length $l$ connected in series between a source $(T_1 = 100^o C)$ and a sink $(T_2 = 0^o C)$ as shown in figure. The rod is laterally insulated If $G_A$ and $G_B$ are the temperature gradients across the rod $A$ and $B$, then
Which of the following factors affect the thermal conductivity of a rod?
The dimensional formula for thermal resistance is
rod of $40\, cm$ in length and temperature difference of ${80^o}C$ at its two ends. $A$ nother rod $B$ of length $60\, cm$ and of temperature difference ${90^o}C$, having the same area of cross-section. If the rate of flow of heat is the same, then the ratio of their thermal conductivities will be
Four rods of same material and having the same cross section and length have been joined, as shown. The temperature of junction of four rods will be........ $^oC$