A 10°C increase in the operating temperature can decrease a DC motor's life expectancy by what percentage?

A 10°C increase in the operating temperature of a DC motor can decrease its life expectancy by approximately half, or 50%. This relationship is based on the accelerated aging of electrical components due to higher temperatures. As the operating temperature rises, the insulation materials and other components in a motor experience increased deterioration rates, leading to more rapid degradation of performance and eventual failure.

This concept is rooted in the Arrhenius Equation, which describes how a chemical reaction rate increases with temperature. For many electronic components, a temperature rise can significantly shorten their operational life. It is often stated that for every 10°C increase in temperature, the lifespan of a motor might be reduced by about 50%. Therefore, recognizing that the life expectancy diminishes sharply with rising temperatures underscores the importance of heat management in electrical systems and motor applications.

In the context of the other choices, while various approximations might suggest different rates of decrease, empirical data and studies consistently illustrate that a 10°C increase has such a pronounced effect, validating the assertion that the correct answer is a 50% reduction in life expectancy.