Passage IV

A blackbody is an object that absorbs all of the radiation that strikes it. The blackbody also emits radiation at all wavelengths; the emitted radiation is called blackbody radiation. The brightness of blackbody radiation at a given wavelength depends on the temperature of the blackbody. A graph of brightness versus wavelength for a blackbody is called a blackbody curve. Blackbody curves for the same blackbody at 3 different temperatures are shown in the figure below.

18. The area under each blackbocly curve gives the total amount of energy emitted every second by 1 m2 of the blackbody. Which of the following correctly ranks the 3 curves, from greatest to least, according to the total amount of energy emitted every second by 1 m2 of the blackbody at the wavelengths shown ?

Answer and Explanation

Your Answer is

Correct Answer is J

Explanation

It can be seen from the question stem that the area covered by the curve is the energy released by the blackbody of 1 m2 per second. It can be seen from the figure that the 500 K curve covers the largest area, and the 300 K curve covers the smallest area