(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 10-2.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

10-2.Heat Transfer

Subtopic

Heat Conduction and Thermal Conductivity

Previous Year

AIEEE 2012 Paper All AIEEE years →

In Searle's method for finding the thermal conductivity of metals,the temperature gradient along the bar:

Easy

View Solution

The two opposite faces of a cubical piece of iron (thermal conductivity $= 0.2 \text{ CGS units}$) are at $100^{\circ}C$ and $0^{\circ}C$ in ice. If the area of a surface is $4 \text{ cm}^2$,then the mass of ice melted in $10 \text{ minutes}$ will be ...... $\text{gm}$.

Medium

View Solution

$A$ heat flux of $4000 \, J/s$ passes through a rod of length $10 \, cm$ and cross-sectional area $100 \, cm^2$. The thermal conductivity of copper is $400 \, W/m^{\circ}C$. The ends of the rod must be maintained at a temperature difference of ....... $^{\circ}C$.

Easy

View Solution

The two ends of a metal rod are maintained at temperatures $100 ^\circ C$ and $110 ^\circ C$. The rate of heat flow in the rod is found to be $4.0 \ J/s$. If the ends are maintained at temperatures $200 ^\circ C$ and $210 ^\circ C$,the rate of heat flow will be.... $J/s$

MediumAIPMT 2015

View Solution

The thermal conductivity of copper is $9$ times that of steel. Find the temperature of the junction of copper and steel in the composite rod as shown in the figure (in $^oC$).

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

In Searle's method for finding the thermal conductivity of metals,the temperature gradient along the bar:

The two opposite faces of a cubical piece of iron (thermal conductivity $= 0.2 \text{ CGS units}$) are at $100^{\circ}C$ and $0^{\circ}C$ in ice. If the area of a surface is $4 \text{ cm}^2$,then the mass of ice melted in $10 \text{ minutes}$ will be ...... $\text{gm}$.

$A$ heat flux of $4000 \, J/s$ passes through a rod of length $10 \, cm$ and cross-sectional area $100 \, cm^2$. The thermal conductivity of copper is $400 \, W/m^{\circ}C$. The ends of the rod must be maintained at a temperature difference of ....... $^{\circ}C$.

The two ends of a metal rod are maintained at temperatures $100 ^\circ C$ and $110 ^\circ C$. The rate of heat flow in the rod is found to be $4.0 \ J/s$. If the ends are maintained at temperatures $200 ^\circ C$ and $210 ^\circ C$,the rate of heat flow will be.... $J/s$

The thermal conductivity of copper is $9$ times that of steel. Find the temperature of the junction of copper and steel in the composite rod as shown in the figure (in $^oC$).

Vedclass Test Series

Exam Paper Generator

Online Exam Module