Compared to the sun, such a filament emits a greater fraction of its radiation in the infrared region of the electromagnetic spectrum. The wavelength of the peak of the distribution is 1082 nanometer. This wavelength lies in the infrared region of the spectrum. Sunlight and light from an incandescent bulb contain all the colors of the visible spectrum. But the intensity distribution over the different colors is different.
Sunlight appears brilliant white while a light bulb looks yellowish.
Assume we have a gas in a container with a movable piston under atmospheric pressure. As we increase the temperature of the gas it expands, its volume increases. The piston moves out. As we cool the gas the piston moves in. The ideal gas law gives us the volume of the gas as a function of temperature.