Sliding rheostat can change the resistance of the connected circuit and continuously change the current, but it cannot accurately know the resistance of the connected circuit. If you need to know the resistance value of the resistor connected to the circuit, you need to use a resistor box.
The resistance box is a kind of rheostat, which can adjust the resistance and display the resistance value of the resistance.
Compared with the sliding rheostat, the sliding rheostat cannot display the resistance value of the connected circuit, but it can continuously change the resistance in the connected circuit. The resistance box can indicate the resistance value of the access circuit, but the change of the resistance value is discontinuous, but it is not as accurate as the sliding rheostat.
Use of resistance box
When in use, connect two terminals into the circuit (both terminals are positive and negative), and adjust the dial to get any resistance between 0 and 0.
Reading method of resistance box
The indication of the indicator point corresponding to each dial is multiplied by the multiple marked on the panel, and then added together, which is the resistance value of the access circuit.