Radiowaves of constant amplitude can be generated with

Options

A. FET
B. filter
C. rectifier
D. oscillator

Answer

To solve the question, we need to determine which device can generate radio waves of constant amplitude. Let's break down the options and analyze them step by step.

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks which device can generate radio waves of constant amplitude. Radio waves are electromagnetic waves, and their amplitude can vary based on the device used to generate them.

2. **Analyzing the Options**:
- **FET (Field Effect Transistor)**: FETs are used in amplifying signals but do not inherently generate waves of constant amplitude. They can produce variable amplitude signals depending on the input.
- **Rectifier**: Rectifiers convert AC (alternating current) to DC (direct current) and are not used to generate radio waves. They also do not produce constant amplitude waves.
- **Filter**: Filters are used to allow certain frequencies to pass while blocking others. They do not generate waves; they modify existing signals.
- **Oscillator**: Oscillators are circuits that generate periodic signals, such as sine waves or square waves, at a constant amplitude. They are specifically designed to produce signals with a stable amplitude over time.

3. **Conclusion**: Based on the analysis, oscillators are the devices that can generate radio waves of constant amplitude. Therefore, the correct answer is **Oscillators**.

### Final Answer:
Radio waves of constant amplitude can be generated with **Oscillators**.

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