Ham Radio General Class Practice Test

In what scenario would a rectifier become less efficient?

1. When used with a load

2. When the peak inverse voltage rating is exceeded

3. When it is connected in series

4. When using high-frequency AC

The correct answer is: When the peak inverse voltage rating is exceeded

The efficiency of a rectifier can decrease significantly when the peak inverse voltage rating is exceeded. Rectifiers are designed to handle a specific maximum reverse voltage amount. If this limit is surpassed, the rectifier can undergo breakdown, which may cause it to conduct in reverse, leading to excessive current flow and potential damage to the rectifier. This scenario results in increased power dissipation as heat instead of transferring energy efficiently to the load. Therefore, when the peak inverse voltage rating is exceeded, the rectifier not only operates inefficiently but could also become non-functional, ultimately hindering its purpose of converting alternating current (AC) to direct current (DC). Other scenarios like being used with a load or in series do not inherently reduce the efficiency unless they lead to overload or other failure conditions. Similarly, using high-frequency AC does not inherently degrade efficiency but may introduce other factors like increased switching loss in certain types of rectifiers.