Fig 38 1 An apparatus used to study

什麼是光電效應？ Fig. 38 -1 An apparatus used to study the photoelectric effect. The incident light shines on target T, ejecting electrons, which are collected by collector cup C. The electrons move in the circuit in a direction opposite the conventional current arrows. The batteries and the variable resistor are used to produce and adjust the electric potential difference between T and C. n n n 陰極(target T)在光的照射下(特別是紫外光)，會更容易放出帶負電 的粒子稱為光電子(photoelectrons)，它們形成電流，稱為光電流 (photoelectric current)。 電池和可變電阻產生逆向電壓，為得是要測量光電子之動能。 當測得電流為零時，此時電壓稱為截止電壓。