Part 1
Spheres P and Q are uniformly constructed from the same material which is a good conductor of heat and the radius of Q is thrice the radius of P. The rate of fall of temperature of P is x times that of Q. When both are at the same surface temperature, the value of x is :
12
Sep
Spheres P and Q are uniformly constructed from the same material which is a good conductor of heat and the radius of Q is thrice the radius of P. The rate of fall of temperature of P is x times that of Q. When both are at the same surface temperature, the value of x [...]
The wall with a cavity consists of two layers of brick separated by a layer of air. All three layers have the same thickness and the thermal conductivity of the brick is much greater than that of air. The left layer is at a higher temperature than the right layer and steady state condition exists. Which of the following graphs predicts correctly the variation of temperature T with distance d inside the cavity?
12
Sep
The wall with a cavity consists of two layers of brick separated by a layer of air. All three layers have the same thickness and the thermal conductivity of the brick is much greater than that of air. The left layer is at a higher temperature than the right layer and steady state condition exists. [...]
Two bodies P and Q have thermal emissivities of ϵ_(P) and ϵ Q respectively. Surface areas of these bodies are same and the total radiant power is also emitted at the same rate. If temperature of P is T_P kelvin then temperature of Q i.e. T_Q is
11
Sep
Two bodies P and Q have thermal emissivities of ϵ_(P) and ϵ Q respectively. Surface areas of these bodies are same and the total radiant power is also emitted at the same rate. If temperature of P is T_P kelvin then temperature of Q i.e. T_Q is A difference of temperature of 25^∘C is equivalent [...]
The intensity of radiation emitted by the sun has its maximum value at a wavelength of 510 nm and that emitted by the North Star has the maximum value at 350 nm. If these stars behave like black bodies, then the ratio of the surface temperature of the sun and North star is:
11
Sep
The intensity of radiation emitted by the sun has its maximum value at a wavelength of 510 nm and that emitted by the North Star has the maximum value at 350 nm. If these stars behave like black bodies, then the ratio of the surface temperature of the sun and North star is: A difference [...]
The spectral emissive power Eλ for a body at temperature T1 is plotted against the wavelength and area under the curve is found to be A. At a different temperature T2 the area found to be 9A. Then λ2 /λ1 is :
11
Sep
The spectral emissive power Eλ for a body at temperature T1 is plotted against the wavelength and area under the curve is found to be A. At a different temperature T2 the area found to be 9A. Then λ2 /λ1 is : A difference of temperature of 25^∘C is equivalent to a difference of. September [...]
Two spherical bodies A (radius 6 cm) and B (radius 18 cm) are at temperature T1 and T2, respectively. The maximum intensity in the emission spectrum of A is at 500 nm and in that of B is at 1500 nm. Considering them to be black bodies, what will be the ratio of the rate of total energy radiated by A to that of B?
11
Sep
Two spherical bodies A (radius 6 cm) and B (radius 18 cm) are at temperature T1 and T2, respectively. The maximum intensity in the emission spectrum of A is at 500 nm and in that of B is at 1500 nm. Considering them to be black bodies, what will be the ratio of the [...]
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respectively. The maximum intensity in the emission spectrum of A is at 500 nm and in that of B is at 1500 nm. Considering them to be black bodies ,
Two spherical bodies A (radius 6 cm) and B (radius 18 cm) are at temperature T1 and T2 ,
what will be the ratio of the rate of total energy radiated by A to that of B? ,
If the temperature of the sun were to increase from T to 2T and its radius from R to 2R, then the ratio of the radiant energy received on earth to what it was previously will be
11
Sep
If the temperature of the sun were to increase from T to 2T and its radius from R to 2R, then the ratio of the radiant energy received on earth to what it was previously will be If the temperature of the sun were to increase from T to 2T and its radius from R [...]
Assuming the sun to be a spherical body of radius R at a temperature of TK, evaluate the total radiant power, incident on earth, at a distance r from the sun.
11
Sep
Assuming the sun to be a spherical body of radius R at a temperature of TK, evaluate the total radiant power, incident on earth, at a distance r from the sun. Assuming the sun to be a spherical body of radius R at a temperature of TK at a distance r from the sun. evaluate [...]
The radiation emitted by a star A is 10,000 times that of the sun. If the surface temperatures of the sun and the star A are 6000 K and 2000 K respectively, the ratio of the radii of the star A and the sun is
11
Sep
The radiation emitted by a star A is 10,000 times that of the sun. If the surface temperatures of the sun and the star A are 6000 K and 2000 K respectively, the ratio of the radii of the star A and the sun is 000 times that of the sun. If the surface temperatures [...]
When the temperature of black body increases, it is observed that the wavelength corresponding to maximum energy changes from 0.26 μm to 0.15 μm. The ratio of the emissive powers of the body at the respective temperatures is:
11
Sep
When the temperature of black body increases, it is observed that the wavelength corresponding to maximum energy changes from 0.26 μm to 0.15 μm. The ratio of the emissive powers of the body at the respective temperatures is: it is observed that the wavelength corresponding to maximum energy changes from 0.26 μm to 0.15 μm. [...]