From Open Education Europa, this looks like a great resource for anybody looking for ancillary resources for Electrical Engineering. It’s a pdf format (and also has a smartphone version) and has a CC BY SA license but the author can be contacted in case that’s a problem.
The description reads:
This booklet on the basics of electrical engineering contains about 90 tasks for DC technology. At the end of the booklet, a result check is attached to the final results of each task.
The following are discussed: – Quantities and Units – Charge, Current, Current Density – Potential, Voltage, Resistance – Temperature Dependence of Resistance – Differential Resistance – Connection of Resistors – Voltage Divider – Current Divider – Capacitance – Inductance – Power, Adjustment, Efficiency – Branch Current Analysis – Superposition – two-pole theory – mesh current analysis – node voltage analysis – circuits with non-linear resistors – four-pole
The actual tasks are compiled in a PDF file (see URL).