- α = 1; ε ≠ 1
- α ≠ 1, ε = 1
- α ≠ 1, ε ≠ 1
- α = 1; ε = 1
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What is the absorptivity of a black body?
Answer: Option 1 Let'
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What is the emissivity of a black body?
Answer: Option 1 Let'
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Depending on the radiating properties, a body will be black when (Where a = absorptivity, p = reflectivity, X = transmissivity.)?
Answer: Option 1 Depending on the radiating properties, a body will be black when P = 0, x = 0 and a = 1 (Where a = absorptivity, p = reflectivity, X...
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The change in length due to a tensile or compressive force acting on a body is given by (where P = Tensile or compressive force acting on the body, $$l$$ = Original length of the body, A = Cross-sectional area of the body and E = Young's modulus for the material of the body)?
Answer: Option 2 Let'
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Thermal diffusivity of a substance is given by (where h = Thermal diffusivity, ρ = Density of substance, S = Specific heat, and k = Thermal conductivity)?
Answer: Option 1 Thermal Diffusivity is defined as the ratio of heat conducted to the heat energy stored per unit volume of a material.the thermal conductivity of a substance divided...
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Fourier's law of heat conduction is (where Q = Amount of heat flow through the body in unit time, A = Surface area of heat flow, taken at right angles to the direction of heat flow, dT = Temperature difference on the two faces of the body, dx = Thickness of the body, through which the heat flows, taken along the direction of heat flow, and k = Thermal conductivity of the body)?
Answer: Option 1 Fourier's law of heat conduction is k. A. (dT/dx) where Q = Amount of heat flow through the body in unit time, A = Surface area of heat...
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The wavelength at which the maximum monochromatic emissive power occurs for a black body, is (where, T = absolute temperature of the black body)?
Answer: Option 2 Let'
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A 'body' which allows the short wavelength incoming solar radiation to enter in, but does not allow long wave length outgoing infra red radiation to escape out is called the?
Answer: Option 2 Let'
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Ceramic coating material for furnace refractory, which increases its emissivity and thus the radiation heat transfer rate in the furnace, comprises of?
Answer: Option 3 Let'
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Absorptivity of a perfect black body is unity. Which of the following has maximum absorptivity?
Answer: Option 4 Let'
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