Write two factors which justify the need of modulating a low frequnecy signal into high frequencies before transmission .

Explanation

To justify the need for modulating a low-frequency signal into high frequencies before transmission, we can consider the following two factors:

### Factor 1: Effective Power Radiated by an Antenna
1. **Understanding Wavelength and Frequency**: The power radiated by an antenna is inversely proportional to the fourth power of the wavelength. This means that as the wavelength increases (which occurs when the frequency decreases), the effective power radiated by the antenna decreases.

2. **Low Frequency Implications**: A low-frequency message signal has a long wavelength. According to the relationship \( v = f \lambda \) (where \( v \) is the speed of the wave, \( f \) is the frequency, and \( \lambda \) is the wavelength), a low frequency results in a longer wavelength.

3. **Power Radiation**: Since the power radiated is inversely proportional to the fourth power of the wavelength, a longer wavelength (due to low frequency) means that the radiated power will be significantly less.
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