Understanding the Unit for Electric Charge

The question asks for the correct unit used to measure electric charge.

Evaluating the Options

Let's examine the provided options:

• Watt-hour: This unit measures energy or work, calculated as power multiplied by time (P × t). It is not a unit of charge.
• Ampere-hour (A⋅h): This unit represents the amount of electric charge transferred by a steady current of one ampere flowing for one hour. It is a valid unit for electric charge, calculated as current multiplied by time (I × t). For example, a 5 A⋅h battery can deliver 5 amperes for one hour or 1 ampere for five hours.
• Voltage: This measures electric potential difference or electromotive force, measured in Volts (V). It is not a unit of charge.
• Ohm-hour: This is not a standard unit for any common electrical quantity. Ohm measures resistance (R).

Conclusion on Electric Charge Unit

Based on the analysis, the Ampere-hour is a recognized unit for electric charge.