To determine the unit of measurement for alternating current frequency, let's examine the options provided:
A. Hertz (Hz)
B. Watts (W)
C. Amps (A)
D. Volts (V)
### Step-by-Step Analysis:
1. Hertz (Hz):
- Hertz is the unit of frequency in the International System of Units (SI). It is defined as one cycle per second. Alternating current (AC) frequency refers to how many cycles the current completes per second. Therefore, frequency is appropriately measured in Hertz.
2. Watts (W):
- Watts are the unit of power. Power is the rate at which energy is used or produced. It is not related to the frequency of the current, but rather to how much energy is being transferred per unit of time.
3. Amps (A):
- Amps are the unit of electric current. It measures the flow of electric charge in a circuit, not the frequency of that current.
4. Volts (V):
- Volts are the unit of electric potential difference or electromotive force. Voltage measures the potential energy per unit charge but does not relate to how often the current changes direction per second (frequency).
### Conclusion:
From the analysis, the unit that correctly measures the frequency of an alternating current is:
- A. Hertz (Hz)
Thus, the correct answer is A. Hertz.
