If you are a student or electronics hobbyist and interested in experimenting with electric circuits or an instructor who is willing to test electric circuits to teach in class room, DCACLab is an online circuit builder who is capable of building DC/AC circuits, you can build circuits with batteries, resistors, wires and other components, then compute Volt, Ampere, Ohm between at any component or connections nodes at board.
Use the components of the virtual lab to exercise practical skills, including operating the circuit using the circuit breaker, testing the capacitor using the multi-meter, locating a short circuit, connecting and operating a basic lighting circuit, and troubleshooting a transformer through continuity measurement.