Error analysis:
1. System error:
(1). The impact of the internal resistance of the ammeter and voltmeter and the contact resistance of the wire on the experiment;
(2). I0 in the least squares method. Error caused by negligence;
(3). The hood is not completely sealed due to the wire connection;
(4). multimeter and rheostat box.
(5). Wire access resistance.
2. Random error:
(1). Multimeter reading is unstable;
(2). Wire access resistance;
(3).Frequent temperature and power supply. voltage fluctuations;
(4). The light intensity is not constant due to slight vibrations on the experimental table;
(5). the light source itself is not absolutely constant.