Rate of heat flow through cross-section of rod shown in figure is ( T₂ > T₁ and thermal condu

English

Gujarati

Hindi

10-2.Transmission of Heat

hard

The rate of heat flow through the cross-section of the rod shown in figure is ($T_2 > T_1$ and thermal conductivity of the material of the rod is $K$)

A

$\frac{{K\pi {r_1}{r_2}\left( {{T_2} - {T_1}} \right)}}{L}$

B

$\frac{{K\pi {{\left( {{r_1} + {r_2}} \right)}^2}\left( {{T_2} - {T_1}} \right)}}{{4L}}$

C

$\frac{{K\pi {{\left( {{r_1} + {r_2}} \right)}^2}\left( {{T_2} - {T_1}} \right)}}{{L}}$

D

$\frac{{K\pi {{\left( {{r_1} + {r_2}} \right)}^2}\left( {{T_2} - {T_1}} \right)}}{{2L}}$

Solution

${r_{eff}} = \sqrt {{r_1}{r_2}} $

$\frac{{dQ}}{{dt}} = \frac{{KA\left( {{T_2} – {T_1}} \right)}}{L} = \frac{{K\pi {r_1}{r_2}\left( {{T_2} – {T_1}} \right)}}{L}$

Standard 11

Physics

Share

Similar Questions

Four conducting rods are joined to make a square. All rods are identical and ends $A, B$ and $C$ are maintained at given temperatures. choose $INCORRECT$ statement for given arrangement in steady state. (value of $\frac {KA}{L}$ is $1\frac{J}{{{S^o}C}}$ , symbols , have their usual meaning)

medium

In variable state, the rate of flow of heat is controlled by

easy

In the Arctic region, hemispherical houses called Igloos are made of ice. It is possible to maintain a temperature inside an Igloo as high as $20^{\circ} C$ because

medium

(KVPY-2012)

The quantity of heat which crosses unit area of a metal plate during conduction depends upon

easy

A partition wall has two layers $A$ and $B$ in contact, each made of a different material. They have the same thickness but the thermal conductivity of layer $A$ is twice that of layer $B$. If the steady state temperature difference across the wall is $60K$, then the corresponding difference across the layer $A$ is ……. $K$

medium