To calculate potential differences around loops in electrical circuits, apply Kirchhoff's voltage law, which states that the sum of the potential differences in a closed loop must equal zero. The currents i1, i2, and i6 are equal due to the conservation of charge, while i3 and i4 can be considered equal as well. The equation can be simplified by omitting currents that flow through short circuits, leading to a relationship between the currents and resistances in the circuit. By analyzing the loops and applying mesh analysis, you can derive the necessary equations for solving the circuit. Ultimately, using these principles will help in determining the unknown currents and voltages effectively.