Communication through free space using radio waves takes place over frequency range of

Options

A. Few tens of MHz to a few GHz
B. Few tens of KHz to a few hundreds of KHz
C. Few tens of GHz to a few hundreds of GHz
D. Few hundreds of GHz to few thousands of GHz

Answer

To solve the question regarding the frequency range used for communication through free space using radio waves, we can follow these steps:

### Step 1: Understand the Concept
Radio waves are electromagnetic waves that are used for communication. They can operate over a wide range of frequencies, and different applications use different frequency bands.

### Step 2: Identify the Frequency Range
From the knowledge of radio wave communication, we know that typical communication frequencies for radio waves range from a few tens of megahertz (MHz) to a few gigahertz (GHz).

### Step 3: Analyze the Options
We need to analyze the given options to find the one that matches our identified frequency range (a few tens of MHz to a few GHz).

### Step 4: Evaluate Each Option
- **Option A:** Few tens of megahertz to few gigahertz. (This matches our identified range)
- **Option B:** Few tens of kilohertz to few hundred kilohertz. (This is too low)
- **Option C:** Few tens of gigahertz to few hundreds of gigahertz. (This is too high)
- **Option D:** Few hundreds of gigahertz to few thousands of gigahertz. (This is also too high)

### Step 5: Conclusion
Based on the evaluation, the correct answer is **Option A: Few tens of megahertz to few gigahertz**.

### Final Answer:
The frequency range for communication through free space using radio waves is from a few tens of megahertz to a few gigahertz.

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