The top of a lake gets frozen at a place where the surrounding air is at a temperature of $-20\,^oC$. Then
Medium
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
- 1Inside a closed furnace held at a temperature of $400\,\, K,$ we have a black body. A hole of area $10\,\, cm^2$ is opened in the furnace so that sunlight starts falling on black body. The intensity of sunlight is $2000\, W/m^2.$ In the steady stateView Solution
- 2An object is at a temperature of ${400^o}C$. At what temperature would it radiate energy twice as fast? The temperature of the surroundings may be assumed to be negligibleView Solution
- 3Three rods $AB, BC$ and $AC$ having thermal resistances of $10\, units, \,10 \,units$ and $20 \,units,$ respectively, are connected as shown in the figure. Ends $A$ and $C$ are maintained at constant temperatures of $100^o C$ and $0^o C,$ respectively. The rate at which the heat is crossing junction $B$ is ........ $ \mathrm{units}$View Solution
- 4A cylindrical steel rod of length $0.10 \,m$ and thermal conductivity $50 \,Wm ^{-1} K ^{-1}$ is welded end to end to copper rod of thermal conductivity $400 \,Wm ^{-1} K ^{-1}$ and of the same area of cross-section but $0.20 \,m$ long. The free end of the steel rod is maintained at $100^{\circ} C$ and that of the copper rod at $0^{\circ} C$. Assuming that the rods are perfectly insulated from the surrounding, the temperature at the junction of the two rods is ................... $^{\circ} C$View Solution
- 5View SolutionHeat current is maximum in which of the following (rods are of identical dimension)
- 6Three 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:View Solution
- 7One end of a copper rod of length $1.0\;m$ and area of cross-section ${10^{ - 3}}$ is immersed in boiling water and the other end in ice. If the coefficient of thermal conductivity of copper is $92\;cal/m{\rm{ - }}s{{\rm{ - }}^o}C$ and the latent heat of ice is $8 \times {10^4}cal/kg$, then the amount of ice which will melt in one minute isView Solution
- 8The original temperature of a black body is ${727^o}C.$The temperature at which this black body must be raised so as to double the total radiant energy, is ....... $K$View Solution
- 9View SolutionRelation between the colour and the temperature of a star is given by
- 10If $K_{1}$ and $K_{2}$ are the thermal conductivities $L_{1}$ and $L _{2}$ are the lengths and $A _{1}$ and $A _{2}$ are the cross sectional areas of steel and copper rods respectively such that $\frac{K_{2}}{K_{1}}=9, \frac{A_{1}}{A_{2}}=2, \frac{L_{1}}{L_{2}}=2$.View Solution
Then, for the arrangement as shown in the figure. The value of temperature $T$ of the steel - copper junction in the steady state will be ........... $^{\circ} C$
