Basic knowledge on heat transfer |
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Please tick the correct answers: | |
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Thermal radiators have special properties that differentiate them from other radiation sources. Which are correct? | The strength of the heat radiation (intensity) in a thermal radiator depends on the temperature. The maximum intensity of a temperature is achieved in a so-called black body. |
Since the sun has all colours in the spectrum, it can be described as a coloured body. | |
Red LEDs can replace heat lamps. | |
A grey body behaves like a black body with reduced intensity. | |
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The temperature of a body is doubled. Which statements are true? | The heat radiation of the body increases 16-fold. Assuming the temperature unit is the kelvin. |
The heat radiation of the body increases 16-fold. The temperature unit does not matter since the unit is disregarded. | |
The total heat output of the body is increased 16-fold. | |
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The image below shows lines that represent the radiation intensity against the wavelength. The visible light is indicated as a rainbow gradient. Heat radiation occurs in the range of 0,78-50 µm. Which answers are correct? | |
 | Epsilon (A) < epsilon (B) |
Temperature line (B) > temperature line (A) | |
Line (B) was would be seen as glowing dark red. | |
Line (C) and line (B) have the same temperature, but the emission of (C) is reduced by a smaller coefficient. | |
Line (D) is in the range of heat radiation | |
Line (D) is a thermal radiator. | |
