Which statement about the functionality of the electrical power supply is NOT correct?

The statement regarding the functionality of the electrical power supply that is not correct pertains to the scenario of a blown fuse. When a fuse is blown, it acts as a safety device designed to interrupt the flow of current in the circuit to prevent damage from excessive current, such as that which might occur during a short circuit.

In the situation where the fuse is blown, the AC voltage between points 2 and 3 would not be 230 V. Instead, the circuit would be open, meaning there would be no voltage present across that section because the blown fuse disconnects the flow of electricity. Therefore, the expectation of a 230 V reading across those points is fundamentally incorrect; the absence of continuity caused by the fuse means that voltage cannot be present.

Understanding the roles of the other components helps clarify this: the rectifier converts AC to DC, and the transformer adjusts voltage levels, while the blown fuse’s role is strictly protective, ensuring that no current flows when there’s a fault. Hence, it’s crucial to recognize that the blown fuse means no current flows, and thus voltage measurements across specific points would reflect that condition.