Radio waves of constant amplitude can be generated with:

Options

A. Filter
B. Rectifier
C. FET
D. Oscillator

Answer

To solve the question regarding the generation of radio waves of constant amplitude, we can break down the solution into several steps:

### Step-by-Step Solution:

1. **Understanding Radio Waves**:
- Radio waves are a type of electromagnetic radiation with wavelengths typically ranging from about 1 millimeter to 100 kilometers (or 10^3 meters). They are used in various communication technologies.

2. **Definition of FET**:
- FET stands for Field Effect Transistor. It is a type of transistor that uses an electric field to control the flow of current. FETs are known for their high input impedance and are widely used in amplifiers and oscillators.

3. **Role of Oscillators**:
- An oscillator is an electronic circuit that generates a continuous wave signal, often in the form of sine waves or square waves. Oscillators can produce signals of constant amplitude, which is essential for generating radio waves.

4. **Generating Constant Amplitude**:
- To generate radio waves of constant amplitude, the oscillator must be designed to maintain a stable output without significant variations. This is typically achieved using feedback mechanisms within the oscillator circuit.

5. **Conclusion**:
- Based on the above understanding, radio waves of constant amplitude can indeed be generated using an oscillator. Therefore, the correct answer to the question is that radio waves of constant amplitude can be generated with a FET oscillator.

### Final Answer:
Radio waves of constant amplitude can be generated with a FET oscillator.

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