Which of the following are symptoms of electrical overload?

The symptoms of electrical overload are indicative of situations where the electrical system is supplying more current than it's designed to handle, which can lead to serious hazards such as fires or equipment damage.

Tripped breakers, blown fuses, and overheating wiring are all direct responses to electrical overload. When too much current flows through a circuit, circuit breakers are designed to trip, cutting off the flow of electricity to prevent overheating and potential fires. Similarly, blown fuses serve a similar protective function by breaking the circuit when the current exceeds safe levels. Overheating wiring is a tangible symptom that indicates excessive current is causing the wires to heat up beyond their rated capacity, which can be dangerous.

While symptoms like bright flickering lights, continuous humming sounds from appliances, and rapid oscillation of electrical current might indicate issues with the electrical system, they are not as definitive in identifying electrical overload specifically. For instance, flickering lights can be caused by circuit issues or bulb problems, humming can stem from normal operation of certain electrical devices, and rapid oscillation of electrical current relates more to instability rather than overload itself. Thus, the most accurate choice that specifically highlights the symptoms of electrical overload is the one mentioning tripped breakers, blown fuses, and overheating wiring.