The capacity of a battery is expressed in terms of?

The capacity of a battery is most commonly expressed in ampere-hours (Ah). This unit signifies the amount of electrical charge a battery can deliver at a specified current over a certain period. For example, a battery rated at 100 ampere-hours could theoretically provide 100 amperes of current for one hour, or 50 amperes for two hours.

This metric is crucial for understanding how long a battery will last under specific load conditions and is an essential consideration for battery selection in various applications, such as in electric vehicles, portable electronics, and renewable energy systems. In contrast, watt-hours (another unit measured in option B) describes how much energy a battery can deliver over time, but it combines both voltage and current. While watt-hours can provide additional context (such as the power output of the battery), the direct measure of capacity itself is best expressed in ampere-hours.

Therefore, while there are other measures of electrical characteristics (like amperes and watts), the standard unit for battery capacity directly relates to the total amount of charge available, which is effectively captured through ampere-hours.