Power Electronical Resistance Calibration Box contains the resistors of different values for estimating and comparing the resistance. The accuracy of the resistance box is very high. The main application of the resistance box is to control the specific value of current to flow through the circuit. The main advantage of the resistance box is that the variable resistances are available at one point. If any circuit requires variable resistances, then there is no need of replacing the resistor. The circuit is directly connected to the resistance box, and by changing the rotary switches, the variable resistances are obtained.