The Seebeck effect is fairly linear; that is, the voltage produced by a heated junction of two wires is directly proportional to the temperature. This means that the temperature of the metal wire junction can be determined by measuring the voltage produced.
Causes[edit] Lightheadedness can be simply (and most commonly) an indication of a temporary shortage of blood or oxygen to the brain due to a drop in blood pressure, rapid dehydration from vomiting, diarrhea, or fever, or from playing a wind instrument.
There are several factors that may contribute to the sensation of light headedness. While these factors are further affected by age, lifestyle patterns, gender, etc, some of the common causes of light headedness include the following. 1  Hunger is one of the most common causes of light headedness.