Final answer:
In the absence of clear context, it's essential to consult a relay's datasheet for exact ratings as they can exceed 500V for controlling inductive loads, but without additional information, the specific upper limit cannot be determined.
Step-by-step explanation:
Relays are used to control a variety of circuit functions and are commonly applied to handle inductive loads such as motors, transformers, or solenoids. When considering the usage of relays for inductive loads, it is crucial to be aware of the voltage rating and the inductive load size that the relay can handle safely and effectively. The general ratings for such applications are not specified in the provided information, and the student's question as to the specific values up to which relays are generally used to control inductive loads (50, 100, 200, 500) lacks context and clarity. Typically, relays are rated according to their contacts' maximum voltage and current ratings, in some cases reaching well above 500V and amperages that can vary based on relay design and contact material.
It's important that you refer to the relay's datasheet or manufacturer's specifications to determine the appropriate ratings for the specific application you have in mind.