If the attenuation through a coaxial cable at 75 MHz is 2.5 dB, what will be the approximate attenuation at 300 MHz?

The attenuation of signals as they pass through coaxial cables tends to increase with frequency. In general, the behavior of attenuation in coaxial cables can often be approximated as being proportional to frequency, especially in the range of typical RF applications.

In this situation, the attenuation at 75 MHz is given as 2.5 dB. When calculating the approximate attenuation at 300 MHz, you can observe that 300 MHz is four times the frequency of 75 MHz. Assuming that the attenuation doubles for every doubling of frequency aligns with typical coaxial cable behavior, you would expect the attenuation to increase in a similar proportion.

Thus, if 75 MHz has an attenuation of 2.5 dB, you would multiply the attenuation by four:

[

2.5 \text{ dB} \times 4 = 10.0 \text{ dB}

]

This aligns with the prediction that as the frequency increases, so does the attenuation. Given this context, the most reasonable choice based on this calculation is indeed 10.0 dB, which is why this answer is correct. The linear relationship of attenuation to frequency allows for such estimates in practical applications concerning cable performance.