Sample interview questions: Can you explain the concept of Peltier effect and its significance?
Sample answer:
Peltier Effect
The Peltier effect is a thermoelectric phenomenon in which a temperature gradient across the junction between dissimilar conductors creates an electromotive force (EMF). This effect is named after the French physicist Jean Charles Athanase Peltier, who discovered it in 1834.
Mechanism
When two dissimilar conductors are joined at one end, charge carriers (electrons or holes) diffuse across the junction. This charge imbalance creates an electric potential or voltage. The direction of the thermoelectric current depends on the type of conductors, with electrons flowing from the hot side to the cold side for p-type semiconductors and holes flowing in the opposite direction for n-type semiconductors.
Significance
The Peltier effect has several significant applications, including:
- Thermoelectric cooling: Peltier coolers utilize the Peltier effect to generate a temperature gradient across a semiconductor junction, resulting in the removal of heat from one side and its transfer to the other side. This technology is employed in small-scale refrigeration and temperature control systems.
- Temperature sensing: Thermocouples are temperature sensors based on the Peltier effect. They consist of two dissimilar… Read full answer