Five wires each of cross-sectional area $A$ and length $l$ are combined as shown. The thermal conductivity of copper and steel are $k_1$ and $k_2$ respectively. The equivalent thermal resistance between $A$ and $C$ is
Five wires each of cross-sectional area $A$ and length $l$ are combined as shown. The thermal conductivity of copper and steel are $k_1$ and $k_2$ respectively. The equivalent thermal resistance between $A$ and $C$ is
- A
$\frac{l}{{\left( {{k_1} + {k_2}} \right)\,A}}$
- B
$\frac{{2l}}{{\left( {{k_1} + {k_2}} \right)\,A}}$
- C
$\frac{{l\,\left( {{k_1} + {k_2}} \right)}}{{{k_1}{k_2}A}}$
- D
$\frac{{l{k_1}{k_2}}}{{k_1^2 + k_2^2}}$
Similar Questions
A solid cube and a solid sphere of the same material have equal surface area. Both are at the same temperature $120\ ^oC$ , then
A solid cube and a solid sphere of the same material have equal surface area. Both are at the same temperature $120\ ^oC$ , then
The temperature of a black body reduces to half of its actual value. By what fraction will the amount of radiations given out reduce?
The temperature of a black body reduces to half of its actual value. By what fraction will the amount of radiations given out reduce?
On heating one end of a rod, the temperature of whole rod will be uniform when
On heating one end of a rod, the temperature of whole rod will be uniform when
A hot liquid kept in a beaker cools from $80\,^oC$ to $70\,^oC$ in $2\, min$. If the surrounding temperature is $30\,^oC$, then the time of cooling of the same liquid from $60\,^oC$ to $50\,^oC$ ........ $\sec$
A hot liquid kept in a beaker cools from $80\,^oC$ to $70\,^oC$ in $2\, min$. If the surrounding temperature is $30\,^oC$, then the time of cooling of the same liquid from $60\,^oC$ to $50\,^oC$ ........ $\sec$
End $A$ of a copper rod is maintained in steam. Chamber $(100\,^oC)$ and other end $B$ is maintained at $0\,^oC$ . Assume $x = 0$ at $A,$ the $T-x$ graph will be (in steady state)
End $A$ of a copper rod is maintained in steam. Chamber $(100\,^oC)$ and other end $B$ is maintained at $0\,^oC$ . Assume $x = 0$ at $A,$ the $T-x$ graph will be (in steady state)