What is the resultant voltage if the signal is 0 dBmV?

The correct answer is based on the interpretation of the decibel-milliVolt (dBmV) scale. A signal measured at 0 dBmV indicates that the voltage level is at a reference point that is defined as 1 mV. The dBmV scale expresses voltage levels in relation to 1 millivolt, with 0 dBmV corresponding precisely to 1 mV.

In this context, dBmV is calculated using the formula:

[ V_{dBmV} = 20 \times \log_{10}\left(\frac{V}{1 , mV}\right) ]

Solving for 0 dBmV:

[ 0 = 20 \times \log_{10}\left(\frac{V}{1 , mV}\right) ]

This means that the voltage (V) equals 1 mV because the logarithm of 1 is 0. Thus, 0 dBmV translates to a voltage level of 1 millivolt, confirming that the resultant voltage when the signal is 0 dBmV is indeed 1 mV.