Use of a multimeter
①Digital multimeter: Before measuring, hit the measurement gear. It should be noted that the range marked on the gear is the maximum value.
②Mechanical multimeter: The method of measuring current and voltage is the same as the mathematical formula, but when measuring negative voltage, the reading must be multiplied by the value on the gear to obtain the measured value. The measurement problem is 200X100=20000Ω=20K, the "Ω" ruler on the dial is from left to right, from big to small, while the others are from left to right, from small to big
