Three conducting rods of same material and cross-section are shown in figure. Temperatures of$ A, D$ and $C$ are maintained at $20^o C, 90^o C$ and $0^o C$. The ratio of lengths of $BD$ and $BC$ if there is no heat flow in $AB$ is:
Medium
Download our app for free and get started
since there is no flow of heat in rod, so temperature of $B$ is equal to temperature at $A$
i.e.,
$\theta_{B}=\theta_{A}=20^{\circ} C$
Heat flowing through $D B$ per second $=$ heat flowing through
i.e., $\frac{K A\left(90^{\circ}-20^{\circ}\right)}{I_{B D}}=\frac{K A\left(20^{\circ}-0^{\circ}\right)}{I_{B C}}$
$\therefore \frac{I_{B C}}{I_{B D}}=\frac{2}{7}$
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
- 1View SolutionIn rainy season, on a clear night the black seat of a bicycle becomes wet because
- 2If the temperature of a black body be increased from ${27^o}C$ to ${327^o}C$ the radiation emitted increases by a fraction ofView Solution
- 3According to Newton’s law of cooling, the rate of cooling of a body is proportional to ${(\Delta \theta )^n}$, where $\Delta \theta $ is the difference of the temperature of the body and the surroundings, and n is equal toView Solution
- 4Two rods one made of copper and other made of steel of the same length and same cross sectional area are joined together. The thermal conductivity of copper and steel are $385\,J\,s ^{-1}\,K ^{-1}\,m ^{-1}$ and $50\,J\,s ^{-1}\,K ^{-1}\,m ^{-1}$ respectively. The free ends of copper and steel are held at $100^{\circ}\,C$ and $0^{\circ}\,C$ respectively. The temperature at the junction is, nearly $.......^{\circ}\,C$View Solution
- 5View SolutionThe quantity of heat which crosses unit area of a metal plate during conduction depends upon
- 6A body cools in $7$ minutes from $60^{\circ}\,C$ to $40^{\circ}\,C$. The temperature of the surrounding is $10^{\circ}\,C$. The temperature of the body after the next $7$ minutes will beView Solution
- 7Distance between sun and Earth is $2 \times 10^{8}\, km ,$ temperature of sun $6000\, K ,$ radius of sun $7 \times 10^{5}\, km .$ If emmisivity of the earth is $0.6,$ find out the temperature of the earth in thermal equilibrium (in $k$)View Solution
- 8Two rods $A$ and $B$ of same cross-sectional are $A$ and length $l$ connected in series between a source $(T_1 = 100^o C)$ and a sink $(T_2 = 0^o C)$ as shown in figure. The rod is laterally insulated If $G_A$ and $G_B$ are the temperature gradients across the rod $A$ and $B$, thenView Solution
- 9Many exoplanets have been discovered by the transit method, where in one monitors, a dip in the intensity of the parent star as the exoplanet moves in front of it. The exoplanet has a radius $R$ and the parent star has radius $100 \,R$. If $I_0$ is the intensity observed on earth due to the parent star, then as the exoplanet transitsView Solution
- 10View SolutionThe value of Stefan’s constant is