Two ends of a rod of length L and a uniform cross-sectional area A are kept at two temperatures T₁

English

Gujarati

Hindi

10-2.Transmission of Heat

easy

The two ends of a rod of length $L$ and a uniform cross-sectional area $A$ are kept at two temperatures $T_1$ and $T_2 (T_1 > T_2)$. The rate of heat transfer,$\frac{ dQ }{dt}$, through the rod in a steady state is given by

A

$\frac{{k\left( {{T_1} - {T_2}} \right)}}{{LA}}$

B

$kLA(T_1-T_2)$

C

$\;\frac{{kA\left( {{T_1} - {T_2}} \right)}}{L}$

D

$\;\frac{{kL\left( {{T_1} - {T_2}} \right)}}{A}$

(AIPMT-2009) (AIIMS-2019)

Solution

$Similar\,to\,I = V/R$

$\frac{{dQ}}{{dt}} = \frac{{kA}}{L}\left( {{T_1} – {T_2}} \right)$

$k=conductivity\,of\,the\,rod.$

Standard 11

Physics

Share

Similar Questions

A copper rod and a steel rod of equal cross-sections and lengths $(L)$ are joined side by side and connected between two heat baths as shown in the figure

If heat flows through them from $x = 0$ to $x = 2L$ at a steady rate and conductivities of the metals are $K_{cu}$ and $K_{steel}$ $(K_{cu} > K_{steel}),$ then the temperature varies as (convection and radiation are negligible)

hard

Temperature difference of $120\,^oC$ is maintained between two ends of a uniform rod $AB$ of length $2L$. Another bent rod $PQ$, of same cross-section as $AB$ and length $\frac{{3L}}{2}$, is connected across $AB$ (See figure). In steady state, temperature difference between $P$ and $Q$ will be close to ………. $^oC$

hard

(JEE MAIN-2019)

Which of the following factors affect the thermal conductivity of a rod?

easy

Ice starts forming in lake with water at ${0^o}C$ and when the atmospheric temperature is $ – {10^o}C$. If the time taken for $1 \;cm$ of ice be $7$ hours, then the time taken for the thickness of ice to change from $1\; cm$ to $2\; cm$ is

medium

The end $A$ of a rod $AB$ of length $1\,m$ is maintained at $80\,^oC$ and the end $B$ at $0\,^oC.$ The temperature at a distance of $60\,\,c.m.$ from the end $A$ is……… $^oC$

medium