(A) Let the thermal conductivity of steel be $K_{steel} = k$. Then,the thermal conductivity of copper is $K_{copper} = 9k$. Let the temperature of the

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

(A) Let the thermal conductivity of steel be $K_{steel} = k$. Then,the thermal conductivity of copper is $K_{copper} = 9k$. Let the temperature of the junction be $\theta$. Since the rods are in series and insulated from the surroundings,the rate of heat flow $(H)$ through both rods must be equal in steady state. $H = \frac{K_{copper} A (100 - \theta)}{L/2} = \frac{K_{steel} A (\theta - 0)}{L/2}$ Since the cross-sectional area $A$ and length $L/2$ are the same for both: $K_{copper} (100 - \theta) = K_{steel} (\theta - 0)$ $9k (100 - \theta) = k \theta$ $900 - 9\theta = \theta$ $10\theta = 900$ $\theta = 90\,^oC$.

Class 11 Physics 2 Thermal Properties of Matter: Heat Transfer Heat Conduction and Thermal Conductivity

Medium

$A$ large cylindrical rod of length $L$ is made by joining two identical rods of copper and steel of length $(\frac{L}{2})$ each. The rods are completely insulated from the surroundings. If the free end of the copper rod is maintained at $100\,^oC$ and that of the steel rod at $0\,^oC$,then the temperature of the junction is........$^oC$ (Thermal conductivity of copper is $9$ times that of steel).

AIEEE 2012 All AIEEE

A
$90$
B
$50$
C
$10$
D
$67$

Explore More

Browse All

Question Bank

All Subjects

Class 11 Questions

Class 11

Physics Questions

Chapter

2 Thermal Properties of Matter: Heat Transfer

Subtopic

Heat Conduction and Thermal Conductivity

Previous Year

AIEEE 2012 Paper All AIEEE years →

$A$ heat source at $T_1 = 10^3\, K$ is connected to another heat reservoir at $T_2 = 10^2\, K$ by a copper slab which is $1\, m$ thick. Given that the thermal conductivity of copper is $0.1\, W\, K^{-1}\, m^{-1}$,the energy flux through it in the steady state is ........... $W\, m^{-2}$.

DifficultJEE MAIN 2019

View Solution

$A$ composite slab is prepared with two different materials $A$ and $B$. The relation between their coefficients of thermal conductivity and thickness is given as $K_A = \frac{K_B}{2}$ and $X_A = 2 X_B$, respectively. If the temperatures of the outer faces of $A$ and $B$ are $75^{\circ} C$ and $50^{\circ} C$ respectively, what will be the temperature of the common surface (in $^{\circ} C$)?

MediumTS EAMCET 2020

View Solution

Two metal rods $P$ and $Q$ have the same length and the same temperature difference between their ends. Their thermal conductivities are $K_1$ and $K_2$,and their cross-sectional areas are $A_1$ and $A_2$ respectively. If the rate of flow of heat through rod $Q$ is three times that in rod $P$,then:

MediumMHT CET 2022

View Solution

$Assertion :$ $A$ brass tumbler feels much colder than a wooden tray on a chilly day.
$Reason :$ The thermal conductivity of brass is more than the thermal conductivity of wood.

EasyAIIMS 2008

View Solution

Two rods of the same length and same cross-sectional area are joined in series. The temperatures at the two ends are as shown in the figure. As we move along the rod,the temperature variation is as shown in the following graph.

Difficult

View Solution

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial

For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free

For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo

Similar Questions

$A$ heat source at $T_1 = 10^3\, K$ is connected to another heat reservoir at $T_2 = 10^2\, K$ by a copper slab which is $1\, m$ thick. Given that the thermal conductivity of copper is $0.1\, W\, K^{-1}\, m^{-1}$,the energy flux through it in the steady state is ........... $W\, m^{-2}$.

Two metal rods $P$ and $Q$ have the same length and the same temperature difference between their ends. Their thermal conductivities are $K_1$ and $K_2$,and their cross-sectional areas are $A_1$ and $A_2$ respectively. If the rate of flow of heat through rod $Q$ is three times that in rod $P$,then:

$Assertion :$ $A$ brass tumbler feels much colder than a wooden tray on a chilly day.$Reason :$ The thermal conductivity of brass is more than the thermal conductivity of wood.

Two rods of the same length and same cross-sectional area are joined in series. The temperatures at the two ends are as shown in the figure. As we move along the rod,the temperature variation is as shown in the following graph.

Vedclass Test Series

Exam Paper Generator

Online Exam Module

$Assertion :$ $A$ brass tumbler feels much colder than a wooden tray on a chilly day.
$Reason :$ The thermal conductivity of brass is more than the thermal conductivity of wood.