This is a two-layer wall, where A and B represent different materials. The same thickness is taken for both the layers, while the thermal conductivity of material A is twice that of material B. Under the conditions of thermal equilibrium, the total temperature difference between the two layers is 36Read more
This is a two-layer wall, where A and B represent different materials. The same thickness is taken for both the layers, while the thermal conductivity of material A is twice that of material B. Under the conditions of thermal equilibrium, the total temperature difference between the two layers is 36°C. As the rate of heat transfer between both the layers should be equal, the temperature difference between both the layers depends on their respective thermal conductivities.
Because material A’s thermal conductivity is higher, there will be relatively easier passage of heat through material A than through B. Therefore the temperature difference shall be smaller when measured across the layer A and larger when calculated across layer B. Since material A has two times the thermal conductivity of B the temperature difference while measured across material A will therefore be half measured across material B.
We have the total temperature difference across the wall, which is 36°C, and we know that the temperature difference across layer B is greater. So we can say that the temperature difference across layer A is 12°C.
So, the temperature difference across layer A is 12°C.
In this case, the primary mode of heat transfer is radiation, since the filament emits thermal radiation that heats the surrounding air and the glass of the bulb. Convection primarily occurs when the heated fluid (like air or water) moves due to temperature differences, but this is not the primary pRead more
In this case, the primary mode of heat transfer is radiation, since the filament emits thermal radiation that heats the surrounding air and the glass of the bulb. Convection primarily occurs when the heated fluid (like air or water) moves due to temperature differences, but this is not the primary process in the case of a light bulb.
The energy distribution in the spectrum of a black body is defined as the dependency of the intensity of the radiated energy emitted by a perfect absorber and emitter of radiation, a black body, on wavelength and temperature. This distribution is described by Planck's law and obeys the following conRead more
The energy distribution in the spectrum of a black body is defined as the dependency of the intensity of the radiated energy emitted by a perfect absorber and emitter of radiation, a black body, on wavelength and temperature. This distribution is described by Planck’s law and obeys the following conditions:
1. Wavelength Dependence: The radiation intensity of a black body at any given temperature depends on the wavelength. Initially, it increases with decreasing wavelength up to a point, then levels off and drops as the wavelength increases further. The peak in intensity shifts towards shorter wavelengths with increasing temperature.
2. Peak Wavelength Shift: According to Wien’s displacement law, the wavelength at which the radiation intensity is maximum is inversely proportional to the temperature of the black body. This means as the temperature of the body increases, the peak of its emission spectrum shifts towards shorter wavelengths (higher frequencies).
3. Total Energy Emission: According to Stefan-Boltzmann law, the total energy emitted per unit surface area of the black body is proportional to the fourth power of its absolute temperature. So, with an increase in temperature, the total energy emitted by the black body increases considerably.
4. Infrared to Ultraviolet: Most radiation from a black body is infrared at the lower temperatures that are not visible. As temperature rises, radiation comes into the range of visible colors, and beyond that temperature the radiation shifts towards ultraviolet, and even above that to various other parts in the electromagnetic spectrum.
Inferences Based on the Black Body Spectrum:
1. Black Body Radiation Depends Only on Temperature Black body radiation’s intensity and spectrum depend entirely on the temperature, according to Planck’s law. The more energetic a black body is, the higher the energy that will be emitted from it and the shorter the wavelength of the maximum emission.
2. Energy is Quantized: The distribution of energy shows the quantized nature of energy levels, as evidenced by Planck’s law, which was one of the key developments that led to the foundation of quantum theory.
3. Ideal Absorber and Emitter: A black body absorbs all falling radiation and then re- emits it in a particular spectrum. This is helpful to understand energy exchanges in systems like stars, earth’s atmosphere, and thermal radiation.
4. Wien’s and Stefan-Boltzmann Laws: This explains the relationship between temperature and radiation, clarifying phenomena ranging from the color of stars-which actually represents their temperature-to the thermal radiation an object throws off.
Black body radiation’s spectrum ensures to explain and quantify the interaction of matter with electromagnetic radiation, leading to important insights into thermodynamics and quantum mechanics.
The energy stored in stretching a string per unit volume is given by the formula: Energy per unit volume = 1/2 × stress × strain This formula is derived from the concept of work done in stretching a material, where stress and strain are related to force and displacement. Click for more solution: httRead more
The energy stored in stretching a string per unit volume is given by the formula:
Energy per unit volume = 1/2 × stress × strain
This formula is derived from the concept of work done in stretching a material, where stress and strain are related to force and displacement.
Drying harvested grains before storage is crucial to prevent spoilage and deterioration. Freshly harvested grains typically have higher moisture content, providing an ideal environment for the growth of microorganisms, insects, and fungi. If stored without drying, the grains can be attacked by pestsRead more
Drying harvested grains before storage is crucial to prevent spoilage and deterioration. Freshly harvested grains typically have higher moisture content, providing an ideal environment for the growth of microorganisms, insects, and fungi. If stored without drying, the grains can be attacked by pests, bacteria, and fungi, rendering them unfit for consumption or germination.
Moisture in stored grains can lead to the development of molds and mycotoxins, posing health risks. Proper drying reduces moisture, inhibits microbial growth, and preserves the quality of the grains, ensuring they remain safe, usable, and suitable for extended storage periods.
A wall has two layers A and B, each made of a different material. Both the layers have the same thickness. The thermal conductivity of the material of A is twice that of B. Under thermal equilibrium, the temperature difference across the wall is 36°C. The temperature difference across the layer A
This is a two-layer wall, where A and B represent different materials. The same thickness is taken for both the layers, while the thermal conductivity of material A is twice that of material B. Under the conditions of thermal equilibrium, the total temperature difference between the two layers is 36Read more
This is a two-layer wall, where A and B represent different materials. The same thickness is taken for both the layers, while the thermal conductivity of material A is twice that of material B. Under the conditions of thermal equilibrium, the total temperature difference between the two layers is 36°C. As the rate of heat transfer between both the layers should be equal, the temperature difference between both the layers depends on their respective thermal conductivities.
Because material A’s thermal conductivity is higher, there will be relatively easier passage of heat through material A than through B. Therefore the temperature difference shall be smaller when measured across the layer A and larger when calculated across layer B. Since material A has two times the thermal conductivity of B the temperature difference while measured across material A will therefore be half measured across material B.
We have the total temperature difference across the wall, which is 36°C, and we know that the temperature difference across layer B is greater. So we can say that the temperature difference across layer A is 12°C.
So, the temperature difference across layer A is 12°C.
See lessIn which of the following processes, convection does not take place primarily?
In this case, the primary mode of heat transfer is radiation, since the filament emits thermal radiation that heats the surrounding air and the glass of the bulb. Convection primarily occurs when the heated fluid (like air or water) moves due to temperature differences, but this is not the primary pRead more
In this case, the primary mode of heat transfer is radiation, since the filament emits thermal radiation that heats the surrounding air and the glass of the bulb. Convection primarily occurs when the heated fluid (like air or water) moves due to temperature differences, but this is not the primary process in the case of a light bulb.
Clcik here:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-11/physics/chapter-10/
Explain the distribution of energy in the spectrum of a black body. What conclusions can be drawn from it?
The energy distribution in the spectrum of a black body is defined as the dependency of the intensity of the radiated energy emitted by a perfect absorber and emitter of radiation, a black body, on wavelength and temperature. This distribution is described by Planck's law and obeys the following conRead more
The energy distribution in the spectrum of a black body is defined as the dependency of the intensity of the radiated energy emitted by a perfect absorber and emitter of radiation, a black body, on wavelength and temperature. This distribution is described by Planck’s law and obeys the following conditions:
1. Wavelength Dependence: The radiation intensity of a black body at any given temperature depends on the wavelength. Initially, it increases with decreasing wavelength up to a point, then levels off and drops as the wavelength increases further. The peak in intensity shifts towards shorter wavelengths with increasing temperature.
2. Peak Wavelength Shift: According to Wien’s displacement law, the wavelength at which the radiation intensity is maximum is inversely proportional to the temperature of the black body. This means as the temperature of the body increases, the peak of its emission spectrum shifts towards shorter wavelengths (higher frequencies).
3. Total Energy Emission: According to Stefan-Boltzmann law, the total energy emitted per unit surface area of the black body is proportional to the fourth power of its absolute temperature. So, with an increase in temperature, the total energy emitted by the black body increases considerably.
4. Infrared to Ultraviolet: Most radiation from a black body is infrared at the lower temperatures that are not visible. As temperature rises, radiation comes into the range of visible colors, and beyond that temperature the radiation shifts towards ultraviolet, and even above that to various other parts in the electromagnetic spectrum.
Inferences Based on the Black Body Spectrum:
1. Black Body Radiation Depends Only on Temperature Black body radiation’s intensity and spectrum depend entirely on the temperature, according to Planck’s law. The more energetic a black body is, the higher the energy that will be emitted from it and the shorter the wavelength of the maximum emission.
2. Energy is Quantized: The distribution of energy shows the quantized nature of energy levels, as evidenced by Planck’s law, which was one of the key developments that led to the foundation of quantum theory.
3. Ideal Absorber and Emitter: A black body absorbs all falling radiation and then re- emits it in a particular spectrum. This is helpful to understand energy exchanges in systems like stars, earth’s atmosphere, and thermal radiation.
4. Wien’s and Stefan-Boltzmann Laws: This explains the relationship between temperature and radiation, clarifying phenomena ranging from the color of stars-which actually represents their temperature-to the thermal radiation an object throws off.
Black body radiation’s spectrum ensures to explain and quantify the interaction of matter with electromagnetic radiation, leading to important insights into thermodynamics and quantum mechanics.
Click here for more:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-11/physics/chapter-10/
Energy stored in stretching a string per unit volume is
The energy stored in stretching a string per unit volume is given by the formula: Energy per unit volume = 1/2 × stress × strain This formula is derived from the concept of work done in stretching a material, where stress and strain are related to force and displacement. Click for more solution: httRead more
The energy stored in stretching a string per unit volume is given by the formula:
Energy per unit volume = 1/2 × stress × strain
This formula is derived from the concept of work done in stretching a material, where stress and strain are related to force and displacement.
Click for more solution:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-11/physics/chapter-8/
Why is it important to dry harvested grains before storage?
Drying harvested grains before storage is crucial to prevent spoilage and deterioration. Freshly harvested grains typically have higher moisture content, providing an ideal environment for the growth of microorganisms, insects, and fungi. If stored without drying, the grains can be attacked by pestsRead more
Drying harvested grains before storage is crucial to prevent spoilage and deterioration. Freshly harvested grains typically have higher moisture content, providing an ideal environment for the growth of microorganisms, insects, and fungi. If stored without drying, the grains can be attacked by pests, bacteria, and fungi, rendering them unfit for consumption or germination.
Moisture in stored grains can lead to the development of molds and mycotoxins, posing health risks. Proper drying reduces moisture, inhibits microbial growth, and preserves the quality of the grains, ensuring they remain safe, usable, and suitable for extended storage periods.
See less