*Question E9A03:
What term describing total radiated power takes into account all gains and losses?*  

*Correct Answer is  C: Effective radiated power*  

### AI Response: (may contain errors)  

The correct answer to the question is **C: Effective radiated power (ERP)**. 

### Explanation of the Correct Answer:
- **Effective Radiated Power (ERP)** is a measure of the total power radiated by an antenna, taking into account both the transmitter power and the gains from the antenna as well as any losses in the system. It is defined as:

$$
ERP = P_T \times G_A
$$

where:
- $P_T$ = transmitter power in watts
- $G_A$ = antenna gain (linear)

This term is crucial in understanding how much power is effectively radiated in a specific direction, which is important for assessing coverage and interference.

### Explanation of Incorrect Choices:
- **A: Power factor**
  - Power factor is a measure of how effectively electrical power is being converted into useful work output. It is not related to the total radiated power of an antenna system.

- **B: Half-power bandwidth**
  - Half-power bandwidth refers to the frequency range over which the power output of a system is at least half of its maximum value. This term is related to the frequency response of a system, not the total radiated power.

- **D: Apparent power**
  - Apparent power is a measure of the total power in an AC circuit, calculated as the product of the root mean square (RMS) voltage and RMS current. It does not account for the gains and losses in an antenna system and is not a measure of radiated power.

### Summary:
- **Effective Radiated Power (ERP)** is the correct term as it encompasses all gains and losses in the radiated power of an antenna.
- The other options relate to different electrical concepts that do not pertain to the total radiated power of an antenna system. 

Understanding these distinctions is key for the Extra Class exam and practical applications in amateur radio.