Perfect Black Bodies And Radiation (physics Only) (GCSE Physics)

For a grey body with emissivity 0.5 at temperature 600 K, and s the Stefan–Boltzmann constant, the emitted power per unit area is

Which phenomenon explains why hot metal glows red then white as it is heated?

Which device gives the closest laboratory approximation to a perfect black body for emission and absorption tests?

A body with high emissivity at infrared wavelengths placed in a cold room will

A perfect black body has emissivity equal to

Why does a black-painted surface feel warmer in sunlight than a white-painted one at the same temperature?

Which statement about emission and absorption for a perfect black body is correct?

If two objects at the same absolute temperature are placed near each other, a perfect black body among them will

Which statement about the cosmic microwave background (CMB) as a black-body spectrum is correct?

The spectral peak wavelength of a perfect black body shifts when its temperature changes. If the temperature increases, the peak wavelength

In thermal imaging, a camera measures emitted infrared intensity to infer temperature. If two objects have equal temperature but different emissivity, the camera will