Two metallic blocks $M_{1}$ and $M_{2}$ of same area of cross-section are connected to each other (as shown in figure). If the thermal conductivity of $M _{2}$ is $K$ then the thermal conductivity of $M _{1}$ will be ]...............$K$ [Assume steady state heat conduction]
JEE MAIN 2022, Medium
Download our app for free and get started
$\Delta T \propto R \propto \frac{\ell}{ k }$,
$\frac{\Delta T _{1}}{\Delta T _{2}}=\frac{\ell_{1}}{ k _{1}} \times \frac{ k _{2}}{\ell_{2}}=\frac{16}{ k _{1}} \times \frac{ k }{8}$
$\frac{20}{80}=\frac{16}{ k _{1}} \times \frac{ k }{8} \rightarrow k _{1}=8 k$
Download our appand get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Similar Questions
- 1The initial temperature of a body is $80°C$ . If its temperature falls to $64°C$ in $5$ minutes and in $10$ minutes to $52°C$ then the temperature of surrounding will be ...... $^oC$View Solution
- 2If wavelength of maximum intensity of radiation emitted by Sun and Moon are $0.5 \times 10^{-4} \,m$ and $10^{-4}\,m$ respectively, then the ratio of their temperature is ............View Solution
- 3When $p$ calories of heat is given to a body, it absorbs $q$ calories; then the absorbtion power of body will beView Solution
- 4View SolutionCooling law is based upon
- 5Four rods of identical cross-sectional area and made from the same metal form the sides of square. The temperature of two diagonally opposite points and $T$ and $\sqrt 2 $ $T$ respective in the steady state. Assuming that only heat conduction takes place, what will be the temperature difference between other two pointsView Solution
- 6Three very large plates of same area are kept parallel and close to each other. They are considered as ideal black surfaces and have very high thermal conductivity. The first and third plates are maintained at temperatures $2\ T$ and $3\ T$ respectively. The temperature of the middle ($i.e.$ second) plate under steady state condition isView Solution
- 7The heat radiated per unit area in $1\,hour$ by a furnace whose temperature is $3000\,K$ is $( \sigma = 5. 7 \times 10^{-8}\,W\,m^{-2}\,K^{-4})$View Solution
- 8In $MKS$ system, Stefan's constant is denoted by $\sigma $. In $CGS$ system multiplying factor of $\sigma $ will beView Solution
- 9$A$ metal rod of length $2$$m$ has cross sectional areas $2A$ and $A$ as shown in figure. The ends are maintained at temperatures $100°C$ and $70°C$ . The temperature at middle point $C$ is...... $^oC$View Solution
- 10An ice cube of dimensions $60\,cm \times 50\,cm \times 20\,cm$ is placed in an insulation box of wall thickness $1\,cm$. The box keeping the ice cube at $0^{\circ}\,C$ of temperature is brought to a room of temperature $40^{\circ}\,C$. The rate of melting of ice is approximately. (Latent heat of fusion of ice is $3.4 \times 10^{5}\,J\,kg ^{-1}$ and thermal conducting of insulation wall is $0.05\,Wm ^{-10} C ^{-1}$ )View Solution